A corner design features two sets of doors that meet at a 90° angle, allowing you to open up a whole section of your home. Best suited to new-builds or extensions due to the large amount of structural steelwork required to support it, the door design includes an in fill post that locks together the pair of doors when they meet at the corner. It then slides away with one set of doors when they are opened, leaving the space free from any pillars or structural posts.
For smaller openings, modern French doors work particularly well and can be more in keeping with a period property. Two or more sets in a rear facade can create a successful link with the outside space, particularly when combined with fixed glazed panels either side.
Aluminium is a popular option as it’s lightweight, strong, won’t expand or contract in different weather conditions, and it can be used to create large doors with slim frames and sight lines. Available in a wide range of finishes, including dual colour (a different hue on the inside and outside), the powder-coated surface is hard-wearing and requires no maintenance. Do bear in mind, however, that specialist finishes will normally involve a longer lead time so you will need to factor this in to your project schedule. For good-quality aluminium bi-folds, prices are in the region of £1,200 for a metre panel; sliding doors cost from around £1,080 per metre.
Wood is ideal for a more traditional look and is very thermally efficient, but the frames will require repainting or varnishing on a regular basis. Timber also tends to add extra bulk to the frame, meaning you’ll lose more of your outside view. Prices can be relatively comparable to aluminium, although bespoke hardwood designs will be pricier. If you’re put off by the upkeep, consider composite models that combine a low-maintenance aluminium exterior and a timber interior frame.
Image: Apropos (0800 328 0033; aproposconservatories.co.uk)
Metal options include traditional Crittall-style steel doors; galvanised, Corten and stainless steels, and architectural bronze, which is a metal alloy. Suppliers such as IQ Glass offer doors in these materials from around £1,400 per sqm. All metal doors, including aluminium, should be thermally broken (meaning there’s a non-metal barrier between the inside and outside of the frame) to prevent excess heat loss and condensation.
Door systems can be either top hung, where the weight of the doors is carried by a lintel or beam above the opening, or bottom hung, in which the doors are supported by the floor rather than a lintel. Bottom-hung systems are increasingly popular for modern aluminium doors, as these designs have minimal tolerance to movement and are more stable fitted to a solid floor construction.
Drainage is an essential consideration if you are planning to have a level threshold between inside and out. The details need to be well planned in advance to ensure that rainwater drains away from the doors rather than back towards the house.
If thermal efficiency is one of your key requirements, consider triple-glazed designs. The framing will be thicker than double-glazed options, and heavier, but they can be a good option if you live on an exposed site, or if you have an older property and need to meet SAP (Standard Assessment Procedure) guidelines relating to the energy and environmental performance of your home.
Image: Klöeber (01487 740 044; kloeber.co.uk)
Need to know
Consider these hi-tech glazing options:
- Solar-control glass – Designed to reflect the sun’s warmth, this is a good choice for south-facing rooms as it prevents the interior overheating.
- Heated glass – A metal oxide coating is applied to the glass and when an electrical charge is passed through the coating it generates warmth, meaning the glazed doors can be used as a main heat source.
- Electrochromic glass – An electrical current alters the colour or tint of the glass, slowly changing from light to dark, to provide solar shading without the need for curtains or blinds.
- Low-iron glass – This offers a more transparent appearance than standard glazing, which has a slight green tint, and is often used for listed-building projects.
Words: Beth Murton