Doors & Windows
In a short interim period between revisions to Approved Document L, we take a breather in this year’s doors and windows overview to look at new products and reflect on relevant design and specification principles and considerations, also taking in ironmongery, blinds and lockers.
Custom-designed doors and ironmongery are fertile ground for invention by architects, especially where they play on qualities such as weight, thickness and strength. But as spec items, doors are often most appealing when glazed, with as little framing as possible. Schüco’s new ASS 77 PD range of motorised, ‘panoramic’ sliding doors is suitable for wide openings with two, three or four leaves, each up to 3.2m wide and 3.5m high. The width of central meeting stiles is 30 mm and the outer frames, which are 200mm deep, are concealed by surrounding construction on all four sides. The track is part of the sliding door leaf, with rollers integrated into the sill profile, allowing the threshold to be flush, avoiding a potential trip hazard. Profile-integrated electronic drive-and-lock push-button technology eliminates the need for door handles and can be activated by switches which are integral, external wall-mounted or by the BMS. A non-insulated aluminium version, ASS 77 PD.NI, is available for internal use and the super-insulated ASS 77 PD.SI, said to have an innovative frame material, is expected to be available next year.
Steel door frames use the inherent strength of their material to minimise section sizes and also offer enhanced fire performance. Schüco Jansen’s new range of Janisol fire doors and screens has now been tested to EN 1364-1 and EN 1634-1 standards. They are manufactured from hot-dip galvanised cold rolled steel sections with special isolators and a fire-retardant core and can achieve an E190 rating, able to retaining their stability and integrity and provide a physical barrier against flame, smoke, heat and hot gases for up to 90 minutes. They have mitred and welded corners and frame depths of 70mm, with typical sight-lines of 132.5mm for frame and opening leaf. Frames are available in all RAL colours and single and double rebated doors are available with or without mid-rails. Maximum leaf sizes for single doors are up to 1,426mm wide x 3,044mm high, with maximum area 5.21 m2 and 1,529mm wide x 2,889mm high in the case of double doors, with maximum area 4.01m2.
Possible infills include various single and double-glazed fire protection units as well as non-glass panels, typically a sandwich of 1mm steel sheet and 36mm of plasterboard.
With the current popularity of folding sliding doors, there is a need for complementary blind products for privacy and glare control. To this end, bi-folding door manufacturer Origin has launched a new range of hand-made blinds. The available options are Roller, Roman, Vertical and Panel. Using discrete remote controls, Origin’s electrically operated roller blind system covers doors independently or in banks.
If you’re an advocate of smooth, seamless circulation through buildings, a minimalist, a hygiene obsessive or if you happen to have a pram to push, luggage, a tea tray or a disability, whether temporary or permanent, a list which must surely include nearly everyone at some stage in their life, the best type of door might be no door at all. Alternatively, automated door opening can be a good compromise. Hold open doors are also a good choice, where doors are required for fire control. Dixon Jones Architects specified DORMA TS93 cam-action closers, with a hold-open function for the atrium of the Quadrant 3 development in London’s Piccadilly has (AJ 24.11. 11).These closers are CE Marked to BS EN 1154 or BS EN 1155 and Certifire Certificated, helping the doorsets to meet the requirements of Approved Document M and BS8300.
Fireco’s Freedor wireless closers allow users to hold open fire doors at any angle, automatically closing them when the fire alarm sounds to prevent the spread of fire and smoke around the building. Fitted at the top of the doors, they are easy to install in new buildings and retrofits, aiming to avoid the expense and disruption associated with hard-wired door closer installation. Minimum battery lives are 12-18 months
Door closers can be too powerful. Astra Door Controls director Philip Gallagher urges architects to fine-tune door closer specification instead of regarding size 3 as suitable for all doors and conditions and argues that it is often necessary to do so in order to comply with the Equality Act, BS 8300 and Approved Document M. ‘Narrower doors, with widths around 750mm, need size 1 or 2 closers or they may be very difficult to open, especially if they aren’t opened at their leading edge, as is so often the case when people are struggling with shopping, buggies, wheelchairs or walking aids,’ says Gallagher. EN1154 Annexe A is often quoted in UK specifications, but there is no reference to this in UK Building Regulations. ‘We have adopted a European standard which does not suit our domestic market,’ says Gallagher.
Detail is everything in quality door and ironmongery design. Hinge manufacturer Cook Brothers’ new Phoenix Interleaf hinges reduce typical gaps for traditional heavy duty continuous hinges from the usual 12mm down to 3mm. These are suitable for 44mm and 54mm timber and metal doorsets and Interleaf hinges completely fill the void between the door and frame, reducing the risk of finger trapping. These hinges have high performance maintenance free polymer bearings, are CE marked and have been successfully tested to BS EN 1935: Grade 14 (160kg). They are also Certifire approved for use on fire doors. For secure environments where the risk of self-harm is a concern, the Interleaf hinge is also available with reduced ligature end caps.
Key-operated entry control is becoming a thing of the past, with various alternatives, including electronic keypads, electric strikes and magnetic locks. Adams Rite’s new eForce-150 keyless battery-operated entry controls, intended for use with its deadbolts, deadlatches and exit devices, can accommodate up to 150 users, including master, supervisor, emergency and one-time codes. Its strong clutch increases protection against vandalism and it is surface-mounted with chrome finish, UV stable keypad material and tidy concealed fixings. The eForce-150’s keypad can be used to programme it in standard, passage and lockout mode. It is suitable for perimeter doors and retrofit applications.
Discussing security standards, ERA Group Technical Director Ben Penson says: ‘Standards are a base to start from, rather than a goal to achieve.’ The highest rating in the new TS 007 security standard is three star, which can be achieved using a combination of handle and cylinder, depending on their individual rating, or by a cylinder alone. If a doorset is fitted with a three-star cylinder, it meets the standard. However, that cylinder only has to prove that it can resist attack using the prescribed methods for three minutes. ‘A cylinder that fails after three minutes and one second has still passed and that’s why product development should use standards as the baseline,’ says Penson. Recent publicity has focused on lock cylinders’ vulnerability to attack by ‘bumping’. ‘We need better ways of protecting the cylinder to prevent the would-be burglar from being able to get to it in the first place and, believing security handles are a better route to protection, we have developed products like Lockguard,’ says Penson. ‘Much higher levels of security can be achieved with a well-designed security handle and by concentrating on the handle, we can introduce additional features that offer considerable benefits to householders.’
There is healthy competition between window manufacturers to achieve high thermal performance standards. The Box, PVC window manufacturer Veka’s latest addition to its Halo System10 range can achieves U-values of 0.66W/m2K with double glazing, 0.42 W/m2K with triple glazing and 0.32W/m2K where cavities are krypton-filled units and sections are foam-filled. Windows are available as open-in, open-out casements or with ‘tilt’n’turn’ mechanisms in a wide range of colours and finishes.
In the curtain walling department, Alu-Timber EFT is a 60mm curtain wall system with horizontally or vertically-capped two-sided structural glazing or four-sided structural glazing.
A wide range of timber mullions and transoms is available, using the material’s inherent low thermal conductivity and strength. Along with larch, pine and eucalyptus, which are engineered, Alu-Timber is also available with oak and ash. Alu-Timber, a sister company of Comar, offers patented screw and magnet option as an alternative to its traditional spring-loaded cleat fixings.
The banks of photovoltaic panels sported by many a retrofit are environmentally all good stuff, but often seem to be lost architectural opportunities. This needn’t be the case. Simon Merrony Architects integrated The Rooflight Company’s neo Solar rooflight with standard PV panels in the refurbishment of a semi in the London Borough of Richmond, providing daylight, natural ventilation and achieving a deliberate architectural appearance.