Some advice/perspective needed please

I have read many posts on this forum over the past few weeks as we looked to buy our first home. It is being sold by receivers with previous owner( investment property) having rented the house and run into arrears. We knew the house would need alot of work. The house also is being sold subject to retention on an unathorised extension to the rear. We could see on viewings that this was not very well constructed about 5yrs ago. We had our offer accepted. We will expect to have the retention issue sorted by mid April. Yesterday I received the engineers report on the house which we commisoned, it gives a daming report on the extenion, poorly construced, no insulatioin, incorrect sheeting roof incorrectly installed, leaking. This is worse that I expect and the engineer, also a fully qualifed archiect advied it might be as well to knock the whole extension and rebuild. Now what would people think about me trying to negotiate a reduction in sale price or objecting to the extension!, though perhaps the latter sounds bizarre. But surely just because some handy man who though he was a builder put up a terrible extension without planning permission, shouldnt be alot to have it all smoothed over by going down retention route. Any advice or commets would be greatfully appreciated

a break down of the cost of additional works to make a house habitable/upto current building standards is often used as a bargaining tool. in this case perhaps a more straight forawrd approach could be used with the auctioneer
why not start your discussion with:

Yesterday I received the engineers report on the house which we commisoned, it gives a daming report on the extenion, poorly construced, no insulatioin, incorrect sheeting roof incorrectly installed, leaking. This is worse that I expect and the engineer, also a fully qualifed archiect advied it might be as well to knock the whole extension and rebuild.

Click to expand...

best of luck

The extension does not seem to be in compliance with Planning or Building Regulations. You should be aware that these are two separate bodies of law, and that compliance of building with planning laws does not automatically mean that it complies with the Building Regulations.
The vendor is trying to sort out the planning issues, and if planning is obtained they will be able to provide you with an Opinion/Cert of compliance with planning permission, issued by their consultant.
You should also insist on the provision of an Opinion/Cert of compliance with Building Regulations.
If the construction is built as badly as you are being told, they will not be able to provide you with such a Opinion/Cert, and the extension thus cannot be shown to have been constructed to comply with the law.
In this case, as lowCO2design has said, you should have your consultant prepare a schedule of costs which will estimate the cost of remedial work or of demolition and rebuilding the extension. This can be used as a bargaining tool to reduce the price of the property.
You also then have to ask yourself, do you want the house with the extension removed, or with the hassle of having to rebuild it?

www.studioplustwo.com

thank you for your reply. We are very happy with the area and are prepared to renovate, to be honest we werent expecting a great report from building survey, just not as damning. Now we are weighing up exactly that question, if we can knock more off the price, then given it is an area we would like to live in as a family, it would probably be worth it. decisions decisions, that you both for your time in replying.
teto