Going up in the World - 1
Ivy Ngeow RIBA
September 2003
Copyright reserved, see legal statement

The roof space, traditionally used for storage, can now be transformed into quiet and bright rooms, perfect for an extra bedroom or office. People would rather convert lofts than move due to the rising property prices and high population densities in London.

Converting the loft increases the value of the property but only by the amount that the loft cost, which would be between £15,000 and £45,000, depending on these factors: type of roof, number of rooms, inclusion of bathroom, and the specifications. Having said that, a poor quality conversion reduces value from the property. People these days are very house savvy. They will simply not want to accept a badly built and low specification extension because it will cost double to improve it.

You can only convert a loft if you have headroom of about 2.4m at the highest point. In properties built after 1965, this is unlikely because they tend to have very shallow roof pitches due to trussed rafters, leaving only a crawl space fit for storage. Houses built before 1965 have rafter and purlin construction where the ridge beam spans between the side walls and rafters carry the roof loading down towards the front and back walls.

Steel joists and new flooring add about 180mm to the level of the existing floor joists, thereby further reducing the headroom inside the loft. When you get up a loft ladder and poke your head through the access hatch, the space may appear very large but a new staircase and landing eat in to the space thereby causing loss of usable floor area.

If you are thinking of converting your roof space, there are two options. First, the cheaper option would be for you to contact a loft conversion company who will provide the entire shebang of services from design to completion. They will take care of all the local authority issues. Make sure that you get at least three detailed, specified and itemised quotes. To do this you must make sure that you yourself know what fittings should be included; for example radiators, power points and light fittings. You must also visit at least two of their previous conversions to avoid being on BBC Watchdog. I cannot stress this enough.

Secondly, the more expensive option would be to appoint an architect. When finding an architect, make sure that you view their portfolio and that you can communicate with them. There are different fee scales, which you should clarify with them: flat fee, an hourly rate or percentage basis, depending on the project. You can hire the cheapest architect but you can never ever make a bad design good. Therefore a strong mutual understanding between client and architect is key to the project. It is a relationship of trust and respect.

An architect can advise you on planning issues. For example, there are many roof forms that are not acceptable to the council. There are numerous possibilities with regards to configurations and design options. Most people have a budget in mind. An architect will be able to sketch and demonstrate several layouts to you based on your budget so that you will be able to use the space most efficiently to suit you and your family. He or she will produce drawings for submission to the council for both planning and building notice applications, and also detailed schedule of works and specifications for going out to tender. These enable different builders to price to the same requirements. They will then go through a fair and square competitive tendering process. Without plans, schedules and specifications, the process is vague and you will never find out what was priced for and what wasn't. The cheapest builder may just have excluded a lot of essential items, and the most expensive may take you to the ceiling of your budget so that you may be out of pocket during emergencies. If you seek out a builder that you already know previously or through your neighbours, he may be able to advise you on ball park costs. These are highly inaccurate fluffy figures for the purpose of borrowing enough money from the bank.

It takes about eight weeks for the council to consider your application. Once you have received permission, you have a choice of running the project yourself or to hire an architect as a project manager. The advantage is that you have an independent contract to the building works because the architect will be employed by you and be working in your best interests. Therefore there is more quality control. The architect's fee for managing the project is usually 15% to 20% of the contract sum (building cost). The larger the building cost, the lower the percentage. If you choose to manage the project yourself, it is of course more stressful as it is a job in itself unless you are an advanced DIYer or you are already in the building industry. Also you have to have organisational skills and a lot of spare time on your hands.

All buildings are made by human beings. This is what everyone forgets. Each is unique. There are inconsistencies and irregularities in every old building. Unforeseen factors like structure or plumbing renewal work cost dearly and cannot be ascertained until opening up. Therefore there is a degree of inaccuracy in terms of cost, time and quantities in any works to existing buildings. If you run the project yourself, there is always a risk that you can specify wrong items or not notice defects, odd fittings, mistakes or unresolved junctions, what we in the trade call 'bad detail'. Basically, you have to ensure that you inspect the building works regularly, specify fittings and finishes correctly, check the contractor's programme, materials and workmanship such that the entire building project is on time and on budget. As the mantra goes, 'do not accept cheap imitations!'

In the next issue: roof forms, stairs, services and local authority issues.