House extensions & planning

I should be able to help you with this one as I am infact an Architect and actually just joined to answer your querry!.

So before you worry about drawings the first thing to check if you havent already is if your extension will require planning permission. There is an area of planning called 'permitted development' which basically covers small extensions. In order to check collect the following information and go to your local authoritys planning department. You will need:

- your address;
- whether your house has been previously extended (since 1948), basically prior to 1948 planning didnt exist and as such previous extensions are considered to be part of the existing house. If you dont know when an extension was added, planning will so ask them for your addresses file and check through, again the on duty planner will be able to help you.
- whether your house is terraced, obviously yours is detached so just let them know that.
- the size and position of the new building (floor area and average height measured externally). To work this out, just measure out in your garden the size approx you think it will be. Height will be important too, so make a rough note of that.
- whether the new building will be within 2 metres of your garden boundary;
- whether the new building will be within 5 metres of the existing dwelling.

Take all of that information to the planning department and you may well find that you dont require planning at all.

If it turns out you do then you will be required to submit a 'Householders Planning Application' The forms for this are generally online and will be able to be downloaded and filled in. Make sure you get this form as the other planning application forms are more indepth and more difficult to fill in if you arent a professional.

In order to submit an application you will indeed require very accurate drawings, and drawn to scales as specified on the form. If you arent qualified to draw them I think you will have problems to be honest.

The application will require 6 copies of each drawing, and generally photographs of the area from the outside to be changed. By all means take photos of neighbours with simular extensions to back up your arguement.

The drawings you will be likely to require are:

1. Site Plan - required to show your house and all the adjoining houses and roads to a scale of 1:1250 and showing the direction of north An accurate red line should be drawn around the development proposed. A blue line should be drawn around any other land you own that lies beyond the immediate boundary of the garden area such as a paddock or field adjacent. This is a very easy drawing to acquire copies of these plans can be brought from Planning department or if you search on the internet for companies who sell ordinance survey maps you can purchase from them. You will then need to add the north point (if you use an ordinance survey map, then norht is always in the direction of the top of the page), and mark on your boundary in red.
2. Block Plan – required to show all the existing buildings on your property however recent , including garages, home extensions, garden sheds and greenhouses on a block plan 1:500 scale. A block plan is essentially a ‘birds eye’ view of the site. Therefore roof lines should be indicated, showing the direction of pitches and whether roofs are gabled or hipped. This plan is essential to show the relationship of the proposal with site boundaries and each neighbouring property. You should also accurately show the position and spread of any existing trees on your plans and state clearly which, if any, are to be felled.
3. Elevations - of both existing and proposed development. For all but the very simplest of developments you are advised that a reputable planning agent is likely to be required to accurately draw such plans to a quality where it is clear what the development will look 1 :100 or 1 :50. These drawings will need to be annotated with the proposed materials, external only, things like, brick to match existing, concrete tiled roof etc.
4. Layout - the arrangement of rooms on each floor; again for both existing and proposed development. These drawings should be drawn to a scale of 1 :50. You can show part plans that just show the extension and the rooms that the extension will be connected onto.

All of the drawings are complex and do really require a professional to draw up for you, they require accurate measurements of your existing bunglow to be taken and all the drawings to be produced to a scale acceptable to planning. It may be possible if you already have a local builder in mind to ask them to draw them for you, but again they will charge but it may be less than an architect will.

One suggestion I do have however for saving a bit of money is, if your neighbours do have the same extensions as what you would like to have, then it may be possible to use their drawings as the survey if you like and just add your proposed extension onto the back. Basically this will potentially save you the cost of a survey and mean that you will effectively just be paying for drawings of the extension to be added on.

If your neighbours do have the same bunglow as you and have been extended then they will have been likely to have employed an architect to draw their plans up. So ask your neighbours and find out the name of the architect.

If you then call the architect, they may allow you to buy the plans from them (architect have the copyright of their work so you must take this route). Normally we charge approx £200 for this. You could then use them as the basis of your drawings, or else ask them to adapt the drawings to your actual house. The fee for this will be considerably less than if you go to a new architect who has to survey the house, draw the existing and then your proposal.

So in short, yes you do need help, check first if you requrie planning permission. Then if you do try to approach the architect who submitted your neighbours plans or else try a builder. But if I were you I wouldnt try to scrimp on doing the drawings yourself as it is a skilled process and if your plans are wrong they will simply be rejected by planning and prolong the cost and process of receiving planning permission.

Hope that helps.

Thats a pleasure, I was hoping I might be able to help somewhere on here someday!!!!

Yep definately try permitted development, it sounds like you may well come within that boundary to me. And if you do get on ok with your neighbours speak to them too, see what they did to get the permission if it was needed.

Let me know how you get on, strangely enough I am London based!

Yes, good informative post by lush.

Just to add to it though. In addition to planning (whether a formal application is required or it is permitted development) you will also need to obtain Building Regulation Approval. Normally for a domestic extension you would use the same plans as submitted for planning, although they do need to be somewhat more detailed with regards to the foundations, structural elements and the like. Also, if you do proceed with the work you may also need to comply with the Party Wall Act 1996. If it is applicable you should not commence work until you have served the requisite notices upon your neighbour(s) and obtained the required consents or settled the “dispute”.

I would suggest that you probably do need professional advice and/or assistance for all or some of the approvals process.