When you are thinking about a home improvement project one of the first questions asked is, “how much is it all going to cost?” By using some on-line tools you can get a ‘ball park’ figure to give a rough idea of how much you have to budget for. All on-line cost calculators should be treated with caution as they can only give a very rough idea of the cost. You would need a builder and possibly other trades to come and give quotes.

When asking for quotes it’s a good idea to at least have quotes from 2 or 3 different builders or the appropriate trades. In the same spirit, this guide allows you to get your rough guide from 3 different renovation cost calculators. Each calculator approaches it differently and asks for varying degrees of information from you. However, as many of these online tools point out, they are not meant to replace someone coming and reviewing the work needing doing and giving a specific quote.

When preparing for these cost calculators and especially when you prepare for getting quotes it is best to write down as much detail as possible to explain what you want, so you can give the same specification to all the contractors quoting, with the intention that you can then compare the quotes. You can ask yourself; how many rooms are involved, total floor area, are the electrics needing re-wiring, how many plugs and sockets are required? Do you know what bathroom suite you want and the kitchen units, then include those costs as well. All this detail can be included in the list of work needing to be quoted for. This is all useful to help you manage the builders and various trades and so help you to manage costs so you don’t overrun on your budget. It’s always a good idea to have a contingency of around 20%, as once floorboards are lifted, rewiring started, old fixtures and fittings taken out then you can discover previously unknown problems.

Before starting any home improvements and getting quotes you should check building regulations and whether planning permission is needed. Check whether your tradesmen are registered with their respective trade body, eg National Federation of Builders.

Use the on-line tools:


Builderstown is perhaps the simplest to use. Here there is a menu like list of various renovation projects. It can give costs for various plumbing jobs, eg you tell it how many radiators you want. You can enter how many kitchens and bathrooms you are wanting to renovate, the total wall area for plastering, you indicate the number of new plug sockets, lights, switches. You enter the floor area for it to calculate the cost of a new floor… Press Calculate and it gives a figure. They are London based builders.


BRS’s cost calculator approach is to ask you to enter the overall floor area of what is needing renovating and to indicate whether it is a single storey and second storey or loft area. It takes you to another page to enter details of how many bathrooms, bedrooms living rooms etc, that you are wanting a quote for, and also what type of finish you are looking for. Then it gives a quote and an option to request a site survey. It does ask for a £30 fee for the site survey, which they say is deducted from the final invoice. They are based in London area and only serve the Greater London area.

There is another approach adopted by Checkyourprice.co.uk. This site gives you an idea of the labour costs involved in your home improvement job. It gives figures for the average labour cost for a list of different renovation projects, eg bathrooms. So it itemises costs to fit and plumb in a wash basin, cost to fit and plumb in a WC and cisterns, cost for a standard shower, electric shower and power shower. It includes other categories of typical renovation/home improvement projects, eg building work, carpentry, kitchen, bedrooms, window installations, electrical work. To work out a total overall cost you would have to include the cost of the various parts and fixtures.

One good feature with all of them is that you can quickly see the effect of altering the extent of your renovation and seeing the effect on the overall cost. Quick and easy.