Typical extension designs

The ‘courtyard’ solution

A third type of extension is a hybrid of the first two, the courtyard. This type of design keeps the advantages of the single sided extension, with the added benefits of the full width type. It achieves this by creating an open courtyard area at the existing rear wall of the house, to provide for light and ventilation, with a link to a new extension beyond.

Pros

• This type is more capable of being subdivided into separate spaces, each with their own access to light and air.
• The courtyard itself can be a nice feature, as it will allow you to keep functional windows on the existing house and bring light into the new build.
• Interesting light effects are possible as several orientations are accessed.

Cons

• Inside, the circulation area (potential dead space) is necessarily increased to allow for the courtyard feature.
• The garden needs to be large as this variant takes up the most garden space of the three options.
• Proportion issues are trickiest here as these sort of extensions are larger and more detached from the existing house.
• The more free form shape of these extensions makes roofing in anything but a flat roof a real challenge.
• The less compact shape and creation of additional glazed external walls to the extension will mean more energy consumption.

Cost issues

• The extended shape and multiple glazed portions of this type will mean higher costs than the other two alternatives, and could make it more difficult to comply with the building regulations on conserving energy. You may have to opt for triple glazing.

The approach that’s right for you

There are many other possibilities beyond these. In a split level house, an extension at a lower floor level can increase the options for bringing in light through clerestory glazing (a series of high level windows). In addition, hybrid variants of the first two kinds can create an ‘L’ shaped extension which allows for an enclosed patio space. The courtyard variant can also be modified, with planning consent, so that, in a smaller property, the courtyard becomes the actual garden.
The clue to which is the right route will always depend on the house you are trying to extend, the available garden space, and what your priorities are. A narrow house may call for a full width solution. The orientation and internal layout of another may suggest the use of a partial width extension. The amount of garden space available and the sort of activities to be enjoyed there will indicate just how much of that space should be left unbuilt. Finally, your own lifestyle and goals for your house as a whole, not just your extension, will help to determine just what form your extension will take.