Tips on building a home extension: Architecture

Conception

Architecture

Planning Permission

Building Control

Getting a Quote

Bathroom

Bedroom

Gallery

The first stage of our extension project was to design the layout. We considered hiering an architect but we were not sure at that point if the project was really going to fly. We did not want to shell out for nothing. There was a distinct possibility that the project could be abandoned because of high costs. The council might reject the planning permission or the building control might say the foundations were not strong enough. So we decided to try to design it ourselves.

It was not difficult for us to decide how to layout the rooms. We wanted to use the main area of new space over the garage as a large bedroom with a sitting area. The existing bathroom would be extended onto the balcony area and an en-suite fits in between. The only design problem we had to resolve was that the new door of the bedroom was going to open out onto the top of the stairs. I decided to extend the landing area back to keep the door clear of the stairway.

Top Tip: Order all the books you can related to what you want to do. The books are cheap compared to the mistakes they help you prevent.

Before going any further I called round a couple of local builders to give me some cost estimates. I described what I was thinking of doing and they both indepedently told me to expect costs to be about £30,000. It sounded remarkably cheap at the time, and given that they were not being asked to commit to anything I assumed the real cost would be higher, but it was good enough to give us the green light to continue.

There are a number of products on the market to help you create building plans on your PC, but I have yet to find one that was written specifically for the UK market. Most of them come from the U.S. and have had the imperial measurements crudely converted to metric. Even worse, the styles and assumed construction methods are very different from what the UK trade offers. Professional architects use AutoCAD but the versions they need are too expensive for one-off use. The market for design software is undoubtedly evolving and you may find what you need. I opted to use pen and paper.

The books I found most useful were two called "Home Extensions". One by Paul Hymers and another by Laurie Williamson. It is also worth getting one of the big books of home plans. They are written for the US market where it is common for people to select a plan for a home from a book and have it built. The books are very cheap because they make their money when people order full-size copies of the plans. I found them useful just as a source of ideas and some clues on how to draw plans.

Equiped with a laser measure devise, I proceeded to painstakingly measure the walls of our house inside and out. I found large sheets of A1 paper in an art shop and drew up the plans with pencil and ruler. The result was crude but it did the job. I found myself wondering if a paid designer would have taken so much trouble measuring the house as I did. It is important to have details like the thickness of walls correct when you get to the building control stage.

Top Tip: Invest in an accurate laser measure device. You are going to have to do a lot of measuring.