embarking on an extension - advice please

melb

hi all as there are many threads on here where things have gone wrong and advice is given about what they should have done i thought i would ask here before we start.

We have planning permission for a 5m x 5m ground floor rear extension at the back of our detached house.

Neighbour objected and will continue to be obstructive wherever possible (they took us to court 15 years ago on boundary dispute and incurred £11,000 legal costs only to be told "this case has been brought on a falsehood" as the opening words of the Judge) so are holding a grudge.

The planning permission said we "may" need to issue a Party Wall Agreement. In order to avoid this we will be using a concrete raft as our foundations will presumably be deeper than theirs as we have a cellar and they don't, although the house is over 3 metres way (just about). The neighbour said as part of their objection that they were worried the building works would harm their fence and patio. We will be extending to within about 18 inches of the boundary at the side as well as internal entrance to the extension.

We have had various builders round to give quotes and have settled on one.

Questions - the guy who drew the plans thought it may be money well spent to employ a surveyor to come round to see if a PWA is required - any thoughts on this?

Can't think of anything else specific but would appreciate any advice to try and protect ourselves and make sure things run as smoothly as possible.

Doozergirl

No doubt your neighbour will make themselves aware of the Party Wall Act. If they are litigious then I would pre-empt and ask a Party Wall Surveyor to assess whether the act applies in your case and write a letter if it doesn’t.

Your neighbour can’t stop you from extending. If the PWA does apply then at least a surveyor will negotiate on their behalf and make them aware of the law.

melb

I was just wondering if you would have an idea of the cost of the services of a Surveyor for this purpose? We have had a quote from a RICS Surveyor to do a sort of project manager role for £2,250 plus VAT which is all itemised and includes liaising with contractors, issuing contracts, making sure we receive all warranties, guarantees etc, plus liaising with building control. i don't think this sounds too bad but as this equates to about 10% of the budget we probably won't go ahead and also there will usually be at least one of us at the house during the work. However he has said he can do as little or as much of the work as we want. Would be interested in your thoughts.

teneighty

With regard to the Party Wall Act the guidance is very clear and from your description your extension is outside the remit of the Act. Any issue with the fence and patio is a civil matter, it would be up to the neighbour to prove that your building work caused any damage. If there is an 18 inch gap between the extension and fence it should be perfectly feasible to undertake the work without causing any damage.

With regard to employing someone to undertake Contract Administration/Project Management. A fee of between 8% and 15% of the contract sum is usual depending on the complexity of the project. Usually your architectural designer would be best placed to undertake the role but as your designer clearly does not understand the Party Wall Act I wonder if they would be up to the Contract Admin.

If you want to try a skeleton service maybe consider employing the surveyor to just issue contract documents, a fixed number of site visits to inspect the work (minimum 4 preferably 6), monthly valuations and issuing of payment certificates (and possibly issuing contract instructions). These would probably cover the areas most likely to go wrong.

Furts

My alarm bells are ringing over this situation. It seems the designer is not clued up, perhaps not competent, perhaps cheap. A competent designer would have discussed all the following actions needed before a builder ever comes to quote for the works. Perhaps this has been done and that is why the RICS surveyor is mentioned?

Planning is just the beginning. Somebody has to consider detailed drawings, a specification, a survey, existing services, and so on... I will not itemise everything but if the consumer is not competent to take this on, and is also baulking at paying somebody to do it, then the saying fools and their money comes to mind.

In general all this would go back to the designer, which also goes back to competence and costings. If the result is not positive then Plan B needs implementing.

melb

We haven't employed a designer as such as the extension is fairly standard I would say from looking at others online and as it is used to be only a sun-room/sitting room there is no need for any plumbing or drainage (although we are debating whether to have wet or dry underfloor heating in there).
We hired an Architect to do drawings which would be acceptable to Planning and which would be useful to the builder.
The Architect then sent the plans/drawings to a Surveyor he knows to look at them and take a view on the Party Wall situation which he stated would not be necessary based on these. We have asked him for a price to come and do a Survey on both properties, taking photos etc and doing measurements so we have something in writing should things go awry.
The use of a concrete raft would negate the need for a PWA we have been led to believe but i am assuming this is more expensive than traditional foundations.
We are very much newbies and are grateful for all advice - we have been stitched up by builders before so are very wary, although we took them to court and recouped all our losses.

teneighty

melb wrote: »

We haven't employed a designer as such as the extension is fairly standard I would say from looking at others online and as it is used to be only a sun-room/sitting room there is no need for any plumbing or drainage (although we are debating whether to have wet or dry underfloor heating in there).
We hired an Architect to do drawings which would be acceptable to Planning and which would be useful to the builder.
The Architect then sent the plans/drawings to a Surveyor he knows to look at them and take a view on the Party Wall situation which he stated would not be necessary based on these. We have asked him for a price to come and do a Survey on both properties, taking photos etc and doing measurements so we have something in writing should things go awry.
The use of a concrete raft would negate the need for a PWA we have been led to believe but i am assuming this is more expensive than traditional foundations.
We are very much newbies and are grateful for all advice - we have been stitched up by builders before so are very wary, although we took them to court and recouped all our losses.

I would suggest the absolute minimum would be to have some more detailed construction plans suitable to get Building Regulations full plans approval before you even get builders quotes. Any uncertainty or ambiguity will only lead to extra costs and delays.

As for employing the surveyor to undertake a condition survey just in case would be a complete waste of money. As would paying a structural engineer to design a raft foundation and the extra construction cost involved.

Furts

I second teneighty, and emphasise you must get a Full Plans Application for Buildings regulations complete with a fully detailed specification and working drawings for anything out of the ordinary, including your wet room and ufh.

Try your very best to avoid a raft construction. This is skilled work, which takes time, that is costly, and requires the services and expense of a structural engineer. There is a common misconception that a raft does no require much, if any, excavation, and can go tight up to a boundary. The reality is different to this, and I say this having done numerous rafts in various locations.

ComicGeek

melb wrote: »

We haven't employed a designer as such as the extension is fairly standard I would say from looking at others online and as it is used to be only a sun-room/sitting room there is no need for any plumbing or drainage (although we are debating whether to have wet or dry underfloor heating in there).

The cost of producing construction drawings for a 'standard' extension is very small compared against the risk of allowing a builder to do whatever the hell they want! Absolutely massive mistake not to do this - I refuse to work on any projects that don't have full construction drawings, it's always goes wrong! There isn't such a thing as 'standard' in construction.

I assume if you're describing it as a sun-room that it has large areas of glazing? So it would be essential to look at Part L1B compliance with respect to excessive glazed areas for extensions, and adjust insulation standards within the extension and/or upgrading standards within the existing house to compensate. Who are you relying on to demonstrate compliance to Building Control on this issue? And this is just one of many issues that need to be considered for approval.