Tick list for a hassle-free extension or conversion

By Nick Elgey, managing director of Cumberland Estate Agents

Last updated at 14:07, Monday, 08 October 2012

Extending your home or converting a loft can be a cost effective way to considerably improve it, increase its value and avoid the disruption and costs of moving.

So where do you start?

Unless you’re involved in the building trade, working out the cost of the project is difficult. A good source of costing is the Building Cost Information Service of the Royal Institution of Chartered Surveyors which publishes The Property Makeover Price Guide, or you could get some idea from www.whatprice.co.uk or try the free estimator on www.growyourhome.com. Always add a contingency allowance of at least 10 per cent in case costs over run.

If you need to borrow money you’ll normally have the choice of either increasing your mortgage or taking out a personal loan. You’ll pay a lower rate of interest for a further advance on your mortgage, but bear in mind that if you spread your repayments over the rest of your mortgage term you’ll probably end up paying more interest overall than with a short-term loan.

If you decide to proceed with the project, approach your neighbours about your plans as you may need their agreement. The Party Wall Act 1996 covers work involving party walls, boundary walls and excavations near neighbouring walls.

You’ll also need to contact your local authority to find out if you need planning permission and if the work needs building regulation approval.

If you need planning permission, decide whether you’re going to employ an architect or surveyor to draw up your plans, find a builder and oversee the project, or whether you just want a professional to provide the plans and do the rest yourself. Check with your builders that they are dealing with building regulations compliance, otherwise you’ll have to submit an application and arrange for an inspector to carry out the required inspections.

If your builder does not supply a contract, you could draw up one yourself setting out the work to be undertaken in as much detail as possible including timescales etc. to be signed by both you and your builder, or you can download a contract free of charge from the Federation of Master Builders website.

Never pay the full price for upfront. Organise payments in stages as parts of the work are completed and hold back at least five per cent of the total until the project is completed to your satisfaction.

Finally, remember to inform your home insurer before you carry out major improvements such as a loft conversions or an extension, otherwise you may that find claims for any damage to the property while the work is going on will be rejected. Consider adding legal expenses cover to your policy as this may pay for any disputes which could arise during the project.