Where to start - extension

Clive_Woody

We currently have a rather old conservatory on the back of our house and we are faced with the decision repair or replace as the roof is leaking.

To be honest we don't get to use it much as in the summer it gets too hot and in the winter it gets too cold, so repair would be a short term fix with limited benefit.

So we are moving towards the replace option. We thought about replacing with another conservatory, but fear of the same old too hot/too cold conundrum means we started thinking about relacing it with an extension, brick built with tiled roof sort of thing.

My question is where to start with this process and figuring out how much this might cost? I assume we would need some sort of architect plans to sketch out the extension, but then do we need planning permission?

Once we have a design presumably we start getting builders round for quotes etc??

Any advice, suggestions, concerns, things to consider would be very much appreciated.

Tucker

You may well not need planning permission as you can build in most cases, a single storey extension to the rear, provided it falls within certain criteria, such as not extending out more than 4 metres etc... Have a google under Permitted Developement and look on you local authority's web site for exact rules.

You WILL need to apply to Building Control and pay for them to oversee the construction.

You don't necessarily needs plans, but are recommended if you intend using a building firm to do the work.

I did an extension on my house just before xmas and just drew my own drawings for buidling control. But I managed my own build getting in each tradesman and did part myself, so plans were not essential.

Once you decide what you want, get someone to do you some drawing and yes, then seek out various quotes. Hopefully you might know someone who's had one done and can recommend a builder?

Other things to consider - if you pay ground rent, you will probably need permision from the land owner, before starting.

It's a messy business digging out the footings, so expect disruption to your garden, driveway etc (assuming you are not looking to use the conservatory base if that were suitable?)

phill99

If you want drawings, you may be as well not to use an architect. They are expensive! Try using a local Draftsman. They are the guys that do most of the drawing in architects offices anyway! Will cost you mush less.

iamcornholio

For a single storey extension, you should not need planning permission as it may well be 'permitted development' (Google)

You will need building regulation approval. You can get this two ways - either get some plans drawn up and approved, or do it under a 'building notice' where by the builder just builds and the council checks it as it goes up.

A building notice is more risk for you as it relies on the builder knowing his stuff, and keeping to the agreed quotation. So you will probably get some plans drawn.

First get a designer around. They will tell you if you need planning permission, if you do he should draw up a plan - both to your requirements and to local planning policy. He should give you a draft design, for approval or amendment prior to submission

The designer will be able to give you an estimate (within £5k) of build costs. Or he should design to your budget

The desinger should advise you on external features and internal layout. You tell him what you want and he should incorporate it as much as possible. Have a think about how you may want to use the room, and ask the designer for his advice on what would be good or bad

There should be no problem with getting PP for a single storey extension (the designer should get pre-application advice if required) although nothing is 100% certain. So you can instruct the designer to prepare and submit the building control drawings so that both approvals come back at the same time and you can start.

A builder will only quote on building control drawings as these have more detail. So as soon as you have these, you can get your quotes.

Use a basic contract with the builder, so you (and the builder) know where you stand on key things like payment, scope, and timescales.

Bear in mind that things may change as the work proceeds, or the building control officer wants things done differently, so expect some price changes if the builder has not quoted for this element of work.

An Architect is overkill and too expensive for this type of work. You want a 'designer' who can be anyone competent to draw plans and who has knowledge of planning and building regs - building surveyor, engineer, architectural technician etc

WestonDave

Its sometimes worth going the other way round - a builder friend of ours tends to put his customers in touch with an ex planning office draftsman who does building drawings for a decent price, and knows what the builder needs to see in the plans. I knew someone else who was a surveyor with a big company that did plans on the side.

If you know a builder that you think might be worth getting to do the job it might be worth starting by getting them round to talk about the possibilities and taking it from there.

Clive_Woody

Tonight "we" are back on the idea of a conservatory, assuming that technology has evolved to make your average conservatory more usable throughout the year.....and cheaper than an extension.

I have heard about all manner of different sorts of glass that is available to help regulate temperature. Can anybody advise on this as an option?

Thanks to all who have replied so far.

planning_officer

Tucker wrote: »

You may well not need planning permission as you can build in most cases, a single storey extension to the rear, provided it falls within certain criteria, such as not extending out more than 4 metres etc...

4 metres for a detached house... 3 metres for a semi or terrace.

sunshinetours

IMO a conservatory will never be as well insulated for the UK climate as a "proper" extension. However the newer coated glasses available certainly can assist in closing the performance gap BUT by the time you have specced up a conservatory to those sort of levels you may well have reached the same levels as a real brick and tile roof extension. With the change ;ast year to the planning laws if you are within permiotted development rights you may not require PP for an extension now

A compromise may be a garden room which is more like a conservatory with a solid roof. You keep your nice views to the garden and light from all the window glass but increase the insulation value (and reduce noise from rain) by having a solid roof. A large chunk of heat loss is often through the plastic or glass roof especially on older conservatories

Best thing may be to get a couple of local conservatory (not national firms) firms round to give an idea of what they can do and how much it will cost and then get a couple of local builder (by recommendation if possible) to give their own thoughts and idea of price

An often mentioned extension ball park figure for costs is between £1000 and £1500 per sq metre depending on where you are in country. Fittiing out the inside obviously may add the cost.
Conservatories seem to range from a couple of £000 upwards depending on what you want

Plenty of posts on here over the years dealing with conservatories and extensions which may also help

Also just re-read your post and you say you don't use it much - the MSE approach may be to knock it down and build a nice patio ?!

Tucker

I stayed well away from considering a conservatory for the reasons you state. Proof that due to it being too cold or too hot, shows it's wasted. Modern glass won't make it any where near on a par with your house or a brick built extension.

At least with an extension you can open it up fully and have it as part of your proper living space.

Beware the amount of glass you intend to use though, if you go down the route of an extension. You can only have 25% of the internal floor space, plus any windows that are making way, as standard. Again, this is because regardless of how high tech the glass is, it loses heat much quicker that brick cavity insulated walls.

My original home drawings were to have it mostly glass fronted. I had to reduce the amount down to fail within the limits for building regs.

Clive_Woody

sunshinetours wrote: »

Also just re-read your post and you say you don't use it much - the MSE approach may be to knock it down and build a nice patio ?!

Thanks, we already have a nice patio though. The reason we don't use the current conservatory is that it is single glazed and leaks, plus for the majority of the year it is too hot or too cold.

dander

I've recommended the Haynes home extension manual a few times on these forums, I don't work for them, honest! It's just that it's a really thorough helpful book that takes you through the whole process of building an extension - as a punter, not as a builder. It really does cover everything including what kind of plans you need, the difference between building control and planning etc.

http://www.haynes.co.uk/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10001&storeId=10001&productId=41763&langId=-1

I'm another one who drew their own plans for an extension. If you're having something simple, then you can save a lot of money at the drawing stage.