Using a Computer to Plan an Extension

Ask a Question
Using a Computer to Plan an Extension

Now that many people have a computer in their home it's become viable to use computer software for planning an extension. There are three ways in which they can be used at the planning stage of an extension build:

  • Visualising your extension in 3D
  • Drawing up plans
  • Building cost estimating
Planning and 3D computer software will involve a fair bit of measuring. Of course you would have to do that measuring if you were using pencil and paper too, but the extra burden of using a software package comes from having to input all the data it requires in order to produce a valid picture or plan, not to mention learning to use the software in the first place. However, you can see the impact of any changes immediately, something that can't be done with pencil and paper.

Many of the 3D packages will also produce plans, line drawings and other views for you to help in your submissions to the planning department. But be careful before spending money on software as many of these packages are very Americanised. It's worth finding one that will deliver plans in a format that's acceptable to UK planning departments.

Estimating Building Costs

Cost estimating software can be very useful. By entering the sizes and volumes of all the different aspects of your extension project and the materials you are going to use you can see the total cost of the build. You can then see the effect of increasing or decreasing the size of a room, for example, or changing the quality or type of a material.

More complex cost estimating software will allow you to input the current prices of the material. This makes the package more useful as you can then see the impact of your bargaining skills. It also means the software will be usable in the future without major outlay, whereas some packages rely on paid updates that apply price movements in the industry.

Planning Permission Checker

Planning Permission Checker

Tell us about your planned extension and find out whether you need planning permission or can build under permitted development.

Try our Planning Permission Checker free, here on this site →

What Range of Software is Available?

Software packages that professional builders and architects use are now available for home computer users although they will cost a fair bit of money. Other lesser packages are available at much lower cost and may well be good enough for your purposes. If you use an architect for the final working plans then you won’t need expensive plan-producing software.

One good place to look is on the free CDs and DVDs that are given away with magazines, either building and interior design magazines or even computer magazines. Quite often software manufacturers will put an old version of their software on a disc of this type in the hope that people will pay for the new version they've just released to get the most up-to-date facilities.

Your situation may be slightly different. ask a question below ↓ and our editorial team will reply with our advice.

Online Impact

The Internet has also changed the way software is being distributed and this has affected building software too. There are now a number of UK sites where you can get a rough estimate of the building costs for your extension. The freebie is offered in the hope that you will then pay to download the full version of the software that they sell.

Although it has to be said that for planning drawings at least it would probably be easier and cheaper to get out a pencil and a ruler. If you factor in the time taken to learn an unfamiliar computer package then it will be easier too.

So assess all the options before embracing computer software.

The Next Step

Planning Permission Checker

Now that you have read through the advice above, you might want to put it into practice. Our Planning Permission Checker lets you tell us about your planned extension and find out whether you need planning permission or can build under permitted development. Try it now →

Ask Extension Build a Question
jab 02/10/2022 at 4:17 pm
We want to convert an old house back into one property.
It was divided into two, pre 1948, so no plans exist from earlier alterations

If all we want to do is re open an internal dividing door way on the ground floor and open one up on the first floor, do we need planning for that ? or do we just ask building control?

A lady from the council in a development office, said we would need full planning but as we aren't doing anything external and are reverting it back to how it was originally built is she correct? we think not?
Bobwouldbebuilder 01/03/2014 at 12:03 pm
HI - can't believe you don't actually list some 3d planning software!

Ask Extension Build a question

Ask our editorial team a question and we will reply with our advice. Tell us as much about your situation as you can: the more detail you give, the more useful our answer can be.

You do not need to use your real name. Please do not include your full address, phone number, email address, or the names of other people. We may edit or remove identifying details for privacy and legal reasons.

Comments are moderated before publication.

Try our free Planning Permission Checker Check Permission for Free