While many experienced architects steer clear of designing extensions, one practice has dedicated itself to small domestic jobs

AS WITH many architectural practices, the people behind Extend began with extensions but then grew into two commercial firms and thought that they would leave small domestic jobs behind.

"But people kept phoning up and asking for extensions," says Johnny Bennett of Bennett McCleary Architects which shares an office space in a redbrick hall in Dundrum with Brennan Brown Architects, and the two practices also run Extend. "We decided to treat extensions like bigger jobs, running a number of them at the same time and combining site visits, seeing about six projects in one day in the same area. We also employ a full-time engineer and quantity surveyor."

They have 100 extensions on the go - designed by a dedicated team - some of which they are seeing through from design to build while others are structures they designed only. They have tried to eliminate the "unknowns", says co-director Liam Brennan, by coming up with a realistic fee for an all-in package that is unlikely to change.

Most people imagine a simple box on the back of their house and price it that way, they say, but the final price actually depends on the work needed to the existing house and how rooms are connected through into the extension. Poor site access can also lift costs by up to 20 per cent, says Brennan.

A guide price for an extension is around €3,000 per sq m (€279 per sq ft) with a 40sq m (431sq ft) extension costing about €150,000-€200,000, although they start at around €100,000 and some clients have spent €600,000 on their extensions.

Extend uses the same groups of builders but if a client brings in their own and the quote is low they will be loathe to work with them. "Such builds should be a certain price to ensure quality," says Brennan.

Most people want the same things from extensions, they say, which is a large kitchen and family room linked to the garden and a main bedroom with en suite. With such family rooms, Extend often persuades clients to have a small retreat space to escape to and relax in.

What is telling is that new extensions tend to be in a different style to the houses they are attached to and many projects involve knocking down an existing extension, which doesn't say much for the original design.

I am shown a contemporary extension on the rear of a new pseudo-Tudor house. Are people braver about extension design because they are hidden?

"People often like to present a facade that is the same as others on the street while being more expressive out back, just like we all are as people," says Bennett.

"If you buy a house you see it about three times and say to yourself, 'it seems to work', but when you live in a house for a while you realise what needs doing and contemporary design reflects how people want to live. Formal diningrooms have gone and people find that having three reception rooms which are all too small, doesn't work. Very few people say that they want to repeat the design of the house and 70 to 80 per cent want a contemporary design."

"Often we are putting design into houses that have never been designed," says Brennan. "Some developers create low-cost homes that are not nice living spaces and we undo previous mistakes such as small back windows beside the garden and a poor relation to the sun and site. People want to open up to the garden, create rooms outside and enjoy every part of their home."

Most clients bring in pictures of what they want, says Bennett, while others have a list and tick off the items as they talk them through with the architects. Extend doesn't have a set style. "We are a non-ego based architectural practice," says Bennett.

"We don't have one style but instead we have a bit of give and take. We can go contemporary or traditional," says Brennan, pointing to pictures of projects that range from timber and glass boxes to cream rendered extensions with sloping roofs.

In fact, says Bennett, people still have a problem with flat roofs even though it is accepted on commercial buildings, "you don't see office blocks with pitched roofs on top", he points out.

Ironically, the older or more important the house the more contemporary the extension. While you can put a traditional extension onto a 1930s house, says Brennan, you need to avoid pastiche on a protected structure.

While they will work with the style that clients want, the advice tends to be on the flow of spaces. "What they suggested made so much sense," says one woman who has an extension by Extend in Rathmines (pictured).

"Some people might imagine that they need a huge extension when in fact they need to rearrange the rooms in their existing house and have a smaller extension," says Bennett.

"A lot of people have set ideas," says Brennan, "but we will point out things that are not advisable because they will cut out light or are of the wrong orientation."

Extend provides 3D computer images and walk-throughs so that there are no surprises: some people, they say, will pretend that they can read drawings when really they won't know what the structure is going to look like.

The trend is towards sustainability. "People feel that they want to do something," says Bennett. And insulation has been the biggest change in the past two years. Underfloor heating can be difficult because it involves ripping up floors but more people are opting for solar panels and heat exchangers. Having worked on so many extensions, Extend has learned what stresses people during work on their homes. They advise clients to move out during the build which typically takes six months. While it may seem cheaper to live in, a contractor could charge more because they have to clear up at the end of each day and also deal with an anxious homeowner on site. They realise it is difficult for people to cope with seeing the back wall of their house come off "and their house getting smashed up". And common panics from people visiting work-in-progress is that the extension looks inadequate. "Bare blockwork always looks small," says Bennett, "all houses look smaller until they are plastered and painted. The satisfaction for us is when people say they are delighted and that the result is better than they imagined."