Apartment Balcony Glazing: Aluminium Doors, Windows and Weatherproof Interfaces

Apartment balcony glazing is the combined system of aluminium doors, windows, fixed panels, thresholds, drainage and protective interfaces that closes the gap between an open balcony and the interior of an apartment, converting an exposed concrete slab into a comfortable, all-weather extension of the home. Unlike glazing on a detached house, balcony glazing in a multi-storey apartment has to sit inside a shared facade, respect a balustrade that often belongs to a separate design package, and survive wind, rain and temperature extremes that intensify with height. The result is a design problem in which weatherproof interfaces matter as much as the glass and the frame itself: every junction between the glazing system, the balustrade, the slab edge and the existing facade is a potential water path and a movement joint.

This guide works through those junctions in order: exposure, doors, windows, balustrade interfaces, thresholds, drainage, wind and weather behaviour, safety glazing, privacy, thermal and acoustic performance, facade movement, installation logistics, maintenance, and the standards framework in Australia and New Zealand. Where relevant it refers to Meichen (MC Windows), a supplier of high-performance, energy-efficient, slim and quiet aluminium window and door systems that has been dedicated to the Australian and New Zealand markets since 2017, operating from a 20,000 square metre manufacturing facility and drawing on 18 to 19 years of industry experience across high-rise residential, townhouse and villa projects.

How Balcony Exposure Shapes the Design

The first design question on any apartment balcony is exposure: which facade the balcony faces, how high above ground it sits, and what combination of weather it will actually experience over a 50-year service life. Two balconies on the same floor of the same building can have very different conditions. One may be sheltered in a concave corner while the other sits fully exposed on the windward side of the tower. The glazing specification that works for one will not necessarily work for the other, which is why exposure analysis comes before product selection, not after.

Solar Gain, Rain and Wind by Orientation

North-facing balconies in the southern hemisphere receive the most consistent solar gain, which is desirable in winter but drives heat and glare in summer. West-facing balconies take the harshest afternoon sun, so glazing choice there has a direct bearing on internal cooling loads. East-facing balconies see morning sun and, in coastal cities, often carry the prevailing sea breeze. South-facing facades in many Australian and New Zealand cities are the most exposed to driving rain, which is why waterproofing detail matters more on the south side than anywhere else on the building. Height compounds all of this: wind speeds increase with elevation, and the pressure a balcony glazing assembly must withstand on the top floor of a tower is categorically different from the pressure on the fourth floor. The wind load applicable to a specific balcony is established by the project structural and facade engineers from the site wind region and building geometry; it is not a generic figure that can be copied between projects.

Driving Rain and the Wet Facade Effect

Balconies are, by design, rain catchments. Water runs down the facade, across the slab edge, and often directly onto the head and jambs of the glazing. Add wind-driven rain at an angle and the weathering is far more aggressive than anything a horizontal roof experiences. This is why balcony glazing is typically specified to the highest water-resistance grade the system can offer, and why the head detail, where the top of the frame meets the slab edge, is the detail most often scrutinised in a design review. Meichen product systems are tested to water tightness of up to 960PA under AS 4284, a figure the company cites as setting industry benchmarks, which gives specification writers a quantified starting point for wet-facade locations. Whether that grade is the right target for a particular project remains a decision for the engineer and the project design specifications.

Sliding and Stacker Doors: The Everyday Boundary

The door leaf is the part of the balcony glazing system the occupants actually use every day, so its operating logic has to fit how the apartment is lived in. Sliding doors remain the default for most apartment balconies: they open without swing space, which matters where the balcony is narrow or the interior is furnished close to the opening. The track sits low on the slab or on a threshold, and the closed panel forms the primary weather boundary between inside and outside.

Sliding Doors for Everyday Weather Sealing

In a sliding configuration one panel is fixed while one or more panels travel along the track. The weather performance of the closed door depends on the seal system, the panel weight and the profile geometry. The MD150 series from Meichen is a non-thermal-break sliding system suited to general balcony use, while the MC140 sliding door belongs to the thermal-break family where insulation performance is the priority. Both approaches use Meichen ultra-slim profile design, which keeps the visual interruption to the view small while retaining the structural depth the seals and the track need. For high-rise applications specifically, Meichen product information emphasises high wind load resistance suitable for high-rise developments. The practical outcome is that balcony doors in taller buildings should be selected from systems engineered and tested for those conditions rather than from a domestic-grade door specified on price alone.

Stacker and Bi-Fold Doors for Full Opening

Where the balcony is wide enough, stacker and bi-fold doors let several panels fold and stack to one side, opening almost the entire frontage and making the balcony feel like part of the room rather than an addition to it. The Ultra Slim Coastal SD205-AS960 from Meichen is a sliding and stacker door system from the ultra-slim coastal family, and its AS960 designation aligns with the 960PA water-resistance figure under AS 4284 referenced in Meichen product data. The MA73 bi-fold door, available with no mullion, is the alternative where a continuous, unbroken opening is the design priority. In apartment applications, stacker and bi-fold doors are usually restricted to lower-exposure locations or to balconies where the engineer has verified the restraint of the open leaves. The number of panels, the stacking arrangement and the wind loading on open leaves are all project-specific decisions that come out of the facade design, not from the door supplier catalogue.

Windows, Fixed Panels and Balustrade-Adjacent Glazing

Slim Windows Around the Door

Most balcony glazing layouts combine a sliding or stacker door with window panels, sliding, awning, tilt and turn, or fixed, to fill the remaining frontage. The SLMA100-20 from Meichen is a slim sliding window from the ultra-slim family, and the MC100 series provides awning, fixed, tilt and turn and double-hung options within the thermal-break range. The mix of operating windows and fixed panels is usually driven by three factors: the number of egress points required, the height of the balustrade interface, and the desire to keep sight lines clear. Low-level panels above the balustrade are the ones that most often take an awning or tilt-and-turn operation, because they can be opened for ventilation even where the balcony is fully exposed to the weather.

Fixed Panels and Continuous Views

Fixed panels are the lightest, simplest and most weather-tight element of any glazing system, which is why apartment facade designs lean on them for the parts of the opening that do not need to operate. In the Meichen range, fixed configurations are available within the MC100 thermal-break series, and the BA150 curtain wall system covers fully fixed, continuous glazed facades where the design calls for an uninterrupted glass plane rather than a conventional window rhythm. For balcony work, fixed panels also do the important job of carrying weather load around the perimeter while the operating leaves handle ventilation and access.

Why Balustrade Interfaces Are Project-Specific

The balustrade is where most balcony glazing projects meet their first complication, because the balustrade and the glazing are usually designed, tendered and certified as separate packages. The glazing system has to meet the balustrade, whether that is an existing balustrade on a renovated building or a new structural or glass balustrade detailed by the facade engineer, and the junction between them must stop water, transfer loads, and allow the two assemblies to move independently of one another.

What the Interface Has to Achieve

A balcony glazing-to-balustrade interface has four jobs. First, it must stop water entering at the point where the frame sits on or wraps the balustrade cap, because that is often the lowest point in the system and where ponding can occur. Second, it must transfer the horizontal loads from wind and from people leaning on the glazing into the structure in the way the balustrade design assumes. Third, it must tolerate relative movement between the balustrade, a structural element reacting with the slab, and the frame, a weather-tight element reacting to temperature. Fourth, it must be achievable on site: a junction that demands millimetre-tolerance precast caps and laser-positioned frames is a junction that will not survive a real installation programme. The specialised solutions from Meichen include balustrades as well as windows and doors, which allows a single supplier to coordinate the handover point. The interface detail itself, however, its dimensions, its load path and its waterproofing strategy, is established project by project by the facade and structural engineers, not by any supplier standard detail.

Why Details Should Not Be Reused Between Buildings

A common failure pattern in apartment balconies is the reuse of a balustrade interface drawn for one building on another. Slab-edge sections differ, balustrade types differ, precast tolerances differ, and the position of the glazing relative to the fall differs. Any design detail that embeds a specific fall, a specific wind region or a specific slab section is valid only for the project it was drawn for. On new work the balustrade interface should appear on the facade general arrangement and on a dedicated detail drawing, signed off by the structural engineer, before the glazing shop drawings are released. That discipline costs a few days in design and removes the most expensive argument on site: who the interface belongs to.

Thresholds, Drainage and Keeping Water Out

The Threshold as the First Line of Defence

Where the balcony door sits, the threshold is the boundary between the wet slab and the dry interior. Apartment thresholds have to negotiate several competing demands at once: low enough to preserve access and step-free movement where the design requires it, strong enough to take foot traffic and weather load, and detailed so that water reaching the track is directed back to the slab rather than into the apartment. In sliding or stacker doors the track channel sits above the threshold, and the drainage logic depends on where the track discharges. Two accepted approaches exist: an internally draining track that runs water back onto the balcony, and an externally discharging track that releases at the outer rail. Which is correct for a project depends on the slab falls, the position of the door and the waterproofing strategy of the slab. That is a decision made in the project design, with the door manufacturer drainage options selected to match.

Drainage Paths, Weep Systems and the Seal

Above the threshold, the glazing system has its own drainage architecture. Water that gets past the outer seal should have a defined path down the frame, out through weep openings, and onto the slab, never into the interior. A tightly sealed system that traps water between two seals without a weep path will eventually find a way into the wall. Meichen systems are built around excellent sealing for acoustic and thermal insulation, and sealing and drainage have to be designed together: a seal applied too aggressively in the wrong position converts a drainage problem into a flooding problem. The water-resistance grade of the system, up to 960PA under AS 4284 for Meichen benchmark systems, describes how hard the weather can be before water is expected to penetrate, but it does not remove the need for drainage detail. Weeped, drained and graded is the standard expectation, and it should be visible in the detail set for every balcony, not assumed from the product data sheet.

Wind, Weather and Structural Behaviour at Height

Wind Loading on Apartment Balconies

A balcony is, structurally, a thin glazed plane cantilevered from the building, and the wind pressure it sees is a function of height, position on the facade, and local acceleration around the corners of the tower. The applicable wind pressure for a specific balcony is established by the project structural and facade engineers using the building wind region, height, shape and the glazing location. It is not a value a window supplier can quote generically, and it should never be copied from another building. What a supplier can state is what its systems are engineered and tested to carry. Meichen product information describes high wind load resistance suitable for high-rise developments, and the certified product series under AS 2047 carry the test data that lets an engineer match system capacity to the calculated demand on each individual project.

The Test Triad: Water, Air, Wind

In practice, balcony glazing is verified against the same triad of properties as any external building envelope: resistance to water penetration, resistance to air leakage, and resistance to wind load, plus the structural behaviour of the operating hardware under repeated cycles. Meichen systems are tested to these properties: water tightness to up to 960PA under AS 4284, excellent airtightness for acoustic and thermal insulation, and high wind load resistance for high-rise use. The 43 certified product series in Australia reflect test data across that family. On an apartment project, the specification writer job is to ensure that the grade demanded at the door heads, at the corners and at the top of the building matches what the selected system is certified to deliver, and that the test data for the exact product series sits in the project file before tender close.

Glazing Safety and Privacy

Where Safety Glazing Is Required

Not all balcony glass carries the same risk, and the Australian standards draw the line by position. AS 2208 defines where safety glazing is required in buildings. The short version for balconies is that glass in door panels, glass low enough to be struck in normal use, and glass in locations where a person could fall through or be injured is treated as a safety glazing location, while a high fixed panel well above reach may not be. AS 1288 is the companion standard that governs how glass in buildings is specified: the glass type, its marking, and the conditions under which a particular product is approved for a particular location. The Australian product series from Meichen are certified against AS 1288 and AS 2208 as well as AS 2047, AS 4284 and AS 4666, so the safety glazing requirement on a balcony project is met by selecting from the certified family rather than by specifying glass in generic terms. The glass type itself, its composition, thickness and marking, is a project-specific selection under AS 1288 driven by location and risk assessment, and it must not be copied between buildings.

Privacy, Neighbours and the View

In dense apartment blocks, privacy is a design constraint as much as a comfort feature. Balconies face other balconies, windows and stairwells, and the glazing choice determines who can see in and who can be seen. Options range from fully clear glass with no treatment, through performance-coated products in double and triple glazing, to privacy treatments such as frit, film or laminated interlayers where the design calls for them. Meichen offers thermal-break systems with double and triple glazing using Low-E coatings, which addresses the thermal boundary while the privacy strategy is handled by the glazing configuration. Which treatment is appropriate is set by the project architectural design and the owners expectations; it is not a standards-driven decision, so it belongs in the design development phase rather than in the tender document. The slim frame design that Meichen emphasises also contributes here: a thinner visible edge means more glass, which can read as more open or more transparent, so frame slimness and the privacy strategy should be assessed together.

Thermal and Acoustic Boundaries

The Balcony as a Thermal Boundary

A glazed balcony changes the thermal behaviour of the apartment. A fully closed balcony with a thermal-break frame and double or triple Low-E glazing holds the internal temperature of the balcony space closer to the living room, reducing the cold bridge effect of a conventional open balcony in winter and the heat trap effect in summer. Meichen thermal-break systems, the MC140 sliding door and the MC100 series in awning, fixed, tilt and turn and double-hung configurations, are designed around that principle, with thermal-break profiles and double or triple glazing with Low-E coatings as the standard offering. Non-thermal-break systems such as the MD150 series remain a legitimate choice where the design priority is cost, weight or water resistance rather than insulation, and the selection between the two is a project-specific performance decision that should be documented in the specification rather than left to site discretion.

Acoustic Comfort, Honestly Stated

Acoustic performance on apartment balconies is usually a response to the site: traffic noise, adjacent building noise, lift plant, and in some locations, noise paths over rooftops. What matters in the glazing system is the combination of airtightness, glass mass and configuration, and the quality of the seals. The honest position, and the one a good specification should force, is that general descriptions are not data. Meichen documentation describes excellent sealing for acoustic and thermal insulation, and the industry test framework under AS 2047 and AS 4284 provides the methodology by which a specific system and a specific glazing combination can be measured for a specific project. Any decibel rating, insulation class or acoustic value for a particular balcony should be obtained from project-specific test data or supplier certification, not assumed from general descriptions. Where a unit has a specific noise target, the specification should call for tested data on the exact door, window and glass combination as installed.

Facade Movement and Long-Term Behaviour

Designing for a Moving Building, Not Just a Frame

A balcony glazing assembly sits on a moving building. The slab expands and contracts with temperature, the balustrade moves with the structure, the frame moves with the air temperature, and the seals have to absorb all of it without tearing or losing compression. Two design responses are standard. First, the frame is typically anchored to the structure at selected points that allow controlled movement, rather than rigidly fixed over its full perimeter; the project detail set shows where the frame is fixed and where it is free to track. Second, the seals are sized to maintain compression across the expected movement range, which is why seal selection is a project-specific engineering input rather than a supplier default. Curtain wall practice formalises this approach at full facade scale, and the BA150 series from Meichen is an example of a system developed for that context. The same logic, fixed points, movement allowances and compression-maintaining seals, applies to balcony glazing on a smaller scale. On high-rise apartment buildings the movement allowances should be reviewed by the facade engineer as part of the design, because the top of the building moves more than the bottom and the top-floor balconies take the difference.

Installation Logistics on Apartment Sites

The gap between a glazing specification and an installed balcony is, for apartment projects, almost entirely logistics. Panels are heavy, fragile and large; access routes are narrow and shared; the weather window on a slab is short; and the building is usually partially occupied or actively being finished by other trades at the same time.

Getting the Panels On Site

The first decision is the route: hoist, external crane, internal lift or service stair. Each panel type has practical size and weight limits on each route, and the glazing supplier must confirm panel sizes against the actual route before shop drawings are released. This is where a supplier supply chain matters. Meichen sources aluminium from AAG, one of Chinas largest production bases with 37 years of experience, and glass from CSG, China Southern Glass, with 42 years of experience and automated production lines. The hardware is specified for the ANZ market specifically, with more than 10 years of experience meeting Australian and New Zealand requirements. That supply chain depth is what lets the factory cut, assemble and glaze panels to a size that will fit the route, rather than field-cutting on a slab edge in the rain. Meichen factory sits in Zhaoqing, Guangdong, and local partnerships in Sydney support the Australian installation side of the business.

Sequence, Tolerances and Handover

The second decision is sequence. Balcony glazing usually follows slab waterproofing and the balustrade, and it should precede the internal fit-out that finishes the floor level at the threshold. The balustrade interface, detailed earlier, is the critical path: the frame cannot be set until the balustrade cap is in place and its tolerance is confirmed. The third decision is the commissioning standard: what is checked before each panel is signed off, how the seals and the drainage are verified, and what documentation is handed over to the building manager. Meichen Australian product series are certified under AS 4666, the installation standard for windows, external doors and louvres, which gives the installation method a reference standard that the project can require in the site quality plan rather than leaving it to installer judgement. The handover set should include the AS 4666 installation record, the supplier test data for the exact product series, and the maintenance schedule for the seals, tracks and hardware.

Compliance: NCC, ABCB and the Australian Standards Package

The NCC and ABCB Framework

The National Construction Code (NCC) is the reference document for building performance in Australia, and the Australian Building Code Board (ABCB) is the body that develops and maintains the NCC and associated model codes and guidance. For balcony glazing, the NCC performance requirements touch the building envelope and its weather resistance, the structural adequacy of the glazing and its supports under applied loads including wind, safety glazing in the locations the standards define, and the acoustic and thermal performance of the boundary where the project brief requires it. The NCC does not name a particular window product. It sets the performance outcome, and the compliance path on a specific project is a combination of the project structural and facade engineering, which calculates the loads and specifies the performance; the standards listed below, which define how products are tested and graded; and the building surveyor acceptance of the compliance documentation. That combination is why the same product series can be specified to different requirements on different apartment projects: the product is constant, the project performance requirement is not.

The Five Australian Standards That Matter on a Balcony

AS 2047 is the testing standard for windows and doors: it defines the test methods and grading for the properties a balcony door and window must demonstrate, including resistance to water penetration, air leakage, wind load, and the mechanical behaviour of the operating hardware. AS 4284 is the performance standard for the performance of windows and external doors, and it is the standard under which Meichen water tightness of up to 960PA is expressed. AS 1288 is the glass in buildings standard: it governs the specification, type and marking of glass for a given location and risk. AS 2208 is the safety glazing standard: it defines the locations in buildings where safety glazing is required, including balcony door panels and low-level panels. AS 4666 is the installation standard: it sets out the requirements for how windows, external doors and louvres are fixed, set and sealed into the building fabric. A specification that names these five standards, together with the NCC performance requirements and the engineer-calculated loads, is a complete and defensible basis for an apartment balcony glazing package. The 43 product series that Meichen has certified in Australia are the pool from which the selected systems are drawn, with certification spanning AS 2047, AS 4284, AS 1288, AS 2208 and AS 4666.

New Zealand References: SNZ TS 4211:2022 and SNZ 4223

The New Zealand market runs on its own standards, and the Meichen product lines certified for New Zealand carry certification against SNZ TS 4211:2022 and SNZ 4223, with 13 product lines certified to that framework. The practical difference for a specifier is that a product series certified for New Zealand is not automatically the same certification as a product series certified for Australia. An apartment project in New Zealand should require the New Zealand certification documentation for the exact product series being used, not the Australian documentation. Where a development spans both markets, the compliance file should carry both, and the differences between them should be noted in the specification so the consent authority or building verifier can trace the compliance path without ambiguity.

CodeMark and Third-Party Verification

Meichen is actively pursuing CodeMark certification, which is the highest level of product certification in Australia. In the interim, international third-party verification through BV, CSI, NATA, AZUMA and INTERTEK provides independent test data that a project can rely on while the CodeMark process completes. For an apartment developer, the practical question at tender is not whether the product is certified in the abstract, but whether the supplier can produce the test data and certification documentation for this product series, to this standard, for this location, within the project documentation deadline. That question should be asked for every standard in the package above, and the answer should sit in the project file before installation starts.

Maintenance and Long Service Life

What the Owner and the Building Manager Actually Do

The maintenance burden of a balcony glazing system falls to two parties. The owner keeps the day-to-day: tracks clear of grit and debris, seals clean, hardware operated within its design range, and any seal distortion, track obstruction or blocked drainage reported promptly. The building manager keeps the long-term: periodic inspection of seals and weep points, verification that the drainage path remains clear, and re-compression or replacement of seals as they age. The frequency of both is a function of the exposure described earlier. A top-floor, west-facing balcony in a coastal city will need a tighter inspection regime than a sheltered, mid-level one, and the building common-property maintenance plan should say so explicitly for the glazing, as it does for the roof and the facade.

Seals, Tracks and Hardware Over Time

The three items that age fastest in any aluminium glazing system are the seals, the tracks and the operating hardware. Meichen use of specialised ANZ hardware, developed with more than 10 years of experience meeting Australian and New Zealand requirements, is aimed directly at that failure mode: hardware matched to the climate and the usage pattern rather than generic import. Seal material is the other ageing item, and it should be specified for the project UV and temperature range rather than assumed. Tracks take the mechanical abuse, grit, foot traffic and the weight of sliding panels, and they are the item most often neglected in maintenance, so the maintenance plan should include a track cleaning and lubrication cycle as a standing line item. Where a seal or hardware component is a wear item, the supplier should provide a replacement schedule and a parts availability commitment as part of the tender documentation, because a balcony glazing system that cannot be maintained is a system that is already failing.

Frequently Asked Questions

What is the minimum wind resistance for an apartment balcony door?

There is no single minimum. The wind load for a specific balcony is calculated by the project structural and facade engineers from the building height, wind region and location, and the door must be selected from a system with test data that meets or exceeds that calculated load. Meichen systems are described as having high wind load resistance suitable for high-rise developments, and the specific test data for the selected product series under AS 2047 is the document that closes the gap between the calculated load and the selected product.

Can an existing apartment balustrade be used with new glazing?

Often, but not automatically. The existing balustrade has to carry the additional loads the glazing transfers to it, and the junction detail has to be designed for that specific balustrade section and its tolerances. If the balustrade is a structural element of the building, the change in loading usually requires the structural engineers sign-off. If the balustrade is in poor condition, installing new glazing may be the moment when it makes economic sense to replace it, and Meichen specialised solutions include balustrades as part of the package.

Which glazing is required for a balcony door in Sydney?

The door panel is a safety glazing location under AS 2208, so the glass in the door must be a safety glazing product specified under AS 1288 for that location. Beyond that, the glass choice, single or double, Low-E coated or not, clear or treated, is a project and performance decision driven by the thermal, acoustic and privacy requirements of the specific apartment. Meichen certified product series cover that range, and the selection is documented in the project glazing schedule.

How do I know the water resistance is adequate for my building?

The water resistance requirement for a specific balcony comes from the project facade design and the exposure analysis, not from a generic table. The system tested grade is the document that answers it. Meichen systems carry water tightness of up to 960PA under AS 4284, and the specification should require that the selected product series tested grade meets or exceeds the grade the facade design calls for at that location, with the test data placed in the project file.

Can the same balcony glazing system be used in Australia and New Zealand?

The product family can be the same, but the certification must match the market. Meichen Australian product series are certified under the Australian standards package, AS 2047, AS 4284, AS 1288, AS 2208 and AS 4666, with 43 product series carrying that certification. Meichen New Zealand product lines are certified against SNZ TS 4211:2022 and SNZ 4223, with 13 product lines carrying that certification. A project in either market should require the certification documentation for the exact product series in that market standards, and a development spanning both markets should carry both files.

Who is responsible for the interface between the glazing and the balustrade?

The interface detail is a project design responsibility, shared between the facade engineer, who details it, and the structural engineer, who verifies the load path. It is documented on the project detail drawings before the glazing shop drawings are released. The glazing supplier provides the frame geometry, the anchoring options and the sealing system around which the detail is built. Where the supplier also provides the balustrade, as Meichen does through its specialised solutions, the coordination between the two is simplified but not removed: the detail is still signed off by the project engineers.

Conclusion

Apartment balcony glazing is, at its core, a weatherproof interface problem wrapped in a frame and a glass specification. The system that works on one balcony may not work on the next, because the exposure, the balustrade, the threshold, the drainage path and the wind load are all project-specific. The standards, the NCC performance requirements, AS 2047, AS 4284, AS 1288, AS 2208 and AS 4666 in Australia, and SNZ TS 4211:2022 and SNZ 4223 in New Zealand, provide the testing and specification framework but not the design. Meichen sits in that framework as a supplier of slim, high-performance aluminium door and window systems, with 43 certified product series in Australia, 13 certified product lines in New Zealand, water tightness of up to 960PA under AS 4284, thermal-break and Low-E glazing options, and a supply chain built around AAG aluminium, CSG glass and dedicated ANZ hardware, with the factory in Zhaoqing and local partnerships in Sydney. The job of the specifier is to take that certified pool, match it against the project calculated loads and performance requirements, and document the match so the building surveyor, the structural engineer and the building manager can all trace it. Done that way, the balcony becomes what it is meant to be: a dry, quiet, all-weather extension of the apartment, not a liability on the facade.