Single storey extension or conservatory? And costing advice too please?

firestorm

We are at the point of putting in an offer on a property. To be adequate for us we would need to add a conservatory or extension to the back of the dining room. The space is approx 11ft wide by 14ft deep. The next door neighbour currently has an extension which is the current boundary, so I take it (am I right in thinking?) a party wall.

Would we be able to utilise this wall should we decide to do an extension, thus saving costs? Or would it be more aggravation than its worth with possible party wall disagreements? Although the current vendor seems to get on quite well with their neighbours, so no reason to believe they would disagree to this.

What are the for's & against's of extension v conservatory? I understand conservatories are cheaper, but i have concerns about whether they can be used year round as we would intend.

Any thoughts on the costings of both too?

Thanks in advance.

capeverde

ok, in a semi, its permitted development to have a single storey extension or conservatory as long as the projection is not more than 3m from the rear building line, as long as the ridge is no more than 5 metres. If you are going to 14 feet you will need planning, but if as you say your neighbour allready has one, it will have set a precedent so it will be a rubber stamping exercise. No problem really with the party wall, other than drainage. Does their wall come above their extension and which way does the roof fall?. you have to take this into account with your roof shape and design. Its difficult without seeing a picture of your neighbours extension, but any small builder will be able to help. Conservatory could be around 7-10k and extension about 10-12k depending on specification.

System

http://forums.moneysavingexpert.com/search.php?searchid=109762049

robert2011

Hi Firestorm, i am a builder also i have pro qualification in Quantity Suveying. An extension will add approx your costs + 15% to the house value, a conservatory will add only 65% of the conservatory cost to your house value = you lose 35% of the spend when selling.
Dont touch your next doors wall, you can build against it but dont incoporate it in your extension!
Total Costs for average extensions like yours 12m2 are £12k-£16k Cons same size about £9K to £12k. South facing conervs are to hot in summer, get a compromise a Sun Room

capeverde

I would challenge you on not using the party wall, providing its been built correctly there is no problem. Creating another wall inside the boundary can raise further issues and may not always be possible. Firstly you may have problems when exposing the neighbours footing depending on how they have been laid. Next you have the issue of overhanding the bricks/blocks and keeping the void tidy. You may also have a problem with the size of the brick reveal on your property and finally there is the added cost. It is doubtful you will be able to make the gap large enough to access it and if not, it will always be a pain in the a-ss.

firestorm

Thanks for all your comments. Very useful. The neighbours wall does go slightly higher than the extension. If im allowed to by site rules I can post a link to the property which has a picture of the rear of the house clearly showing the neighbours extension & where it is in relation to the house we hope to buy.

The costings sound do able too. I assume we would need to get plans drawn up by an architect wouldn't we? Is this expensive?

capeverde

no problem posting a picture of it, would help with advice.

firestorm

Here is a pic of the back of the house. Thanks.

capeverde

wow, thats a biggy! suprised that got planning!! right, theyve got a box guttering down the capped wall, hence its taller than the extension. it gives you options as to which roof pitch you have. personally in this situation, i would go for a conservatory otherwise you will definitely have light issues and it will be cheaper. I would maximise space by utilising their wall and have a centre ridge akin to their design with a gable end. It will enable you to have a blu glass roof as the pitch will be higher than a lean to design. (give polycarb a miss. Depending on which way you are facing you may need roof blinds which can also be built inside the sealed units.

firestorm

Ok, That's very interesting & useful advice. Many thanks. I will definitely keep a note of your suggestions for future reference.

The fact that you suggest a conservatory is great as far as our finances are concerned. We would want to use the room on a daily basis as the main living room. Is this possible? Would we need to get specialist solar glass or something? Think the house might be north facing, so maybe we'll get away without the roof blinds.

Do you suggest we go to one of these specialist conservatory companies to do a package job, or an independent person?

capeverde

no problem with the usage, but will obviously need rads or underfloor heating for the winter. best glass for the roof;

http://www.pilkingtonselfcleaningglass.co.uk/pilkington-activ/blue/

personally I would always use a small to middle sized local company, but take the time to ask for references and contact these people. Best tip ever is that when the installers start, tell them theres an extra 200 quid in it for them at the end if they do an amazing job. I know you shouldnt have to, but it will be the best money you have spent. The important thing with these jobs is the smaller details and finishing off. Pays to be sensible, far better to negotiate down a bit with the company and use this as a sweetener with the installers. Plenty of tea and some bacon sarrnies in the morning does wonders.