Project manage your own loft conversion

You will need the services of an architect and a structural engineer.  These two need to work hand in hand, so you are advised to employ people who have worked together in the past.  If you need an architect, mybuilder.com is a good place to start.  The structural engineer will specify the materials you should use, such as the size of timbers.  Insist on a face-to-face meeting to ensure you understand the details of the build.

If you live in a terrace house or semi-detached house, and are planning on building into a party wall, you will also need to employ a Party Wall Surveyor.

Many loft conversions can be undertaken under Permitted Development rules.   Under this scheme, you can convert your loft by up to 50m³ in a detached house, or by 40m³ within any other home.  There are exceptions to this, so always consult your architect.  If you require planning permission, most decisions are made within eight weeks.  For both routes, you will need to submit architectural drawings.  Allow two to three weeks for these.

At this point, you should also inform your insurer and mortgage lender of your plans.  You may need to pay a small additional insurance premium.

Whether you are planning on selling or staying, this is an important decision.  Adding a new bathroom will typically add 10% to the value of your home.  Once you have four bedrooms, buyers will insist on at least two bathrooms.  En suites are very desirable too.

It is hard to beat a personal recommendation.  If that is not an option, there are various websites onto which you can post jobs and search for builders.  For example, The Federation of Master Builders.  Ideally, the builder you choose will be able to show you a portfolio of work, and provide trusted electricians and plumbers.

Image source: EH Smith

Materials will probably account for more than half of your total costs.  If you have the time, you should shop around.  Loyalty definitely doesn’t pay, as builders’ merchants tend to price items differently.

Before you start the work, you will need to inform Building Control.  Inspections are mostly undertaken by Local Authorities,  but increasingly approved private firms are getting in on the action.  There is little to choose between the two, so go for the cheapest option.

Ask your allocated inspector for a schedule of inspection.  They will need to visit the property a number of times.   For example, to inspect the steel beams, the insulation and the roof.  In addition, they will need to sign off the structural calculations.  Assuming the work is approved, they will issue a Building Control Certificate.  Do not make the final payment to the builder until the work is signed off.