The walls are exterior brick and the interior walls are breeze block. There is no cavity or insulation between the 2 brick layers. The interior walls will have a membrane on with insulation and then plastered. So i assume this counts as a single skin? What price are we talking?

@king12345 Thanks for your reply. I have made a final improved offer of £7800 for the completed porch, which includes a composite front door, the door has been installed. The completed porch includes plastering and electrics. You seem to have some knowledge in this field, am i being unreasonable by offering £7800 when his final quote is £8300, albeit for his error with the calculations. I also have to live with the risk regarding planning. Thanks.

@king12345 The size has been an issue from that start. When the builder came to measure up for the quote we asked him we would like a big porch but within planning regulations. His reply was you can have any size porch you want as you do not need planning permission. We said we would like a porch similar in size to others built in my road. These have also not applied for planning permission. So we agreed 4mX1.4m. However he has built the porch 4mx1.9m, therefore it is a large porch. During the build, it has come to light that planning permission is required, as it exceeds 3m2. In the 9 weeks construction to date, this included 9 days were the builder went on holiday, we did not know when the quote was agreed that the builder was planning on going on holiday.

@King12345 The hipped roof is near completion stage, so it is too late for that option. Good shout with regards to him being a bingo caller. I can not keep up with the amount of quotes. I think a new calculator is required for this builder, although i have an email also saying that he pressed the wrong button on his calculator which 'may' have been one of the causes of his initial mistake.

BankFodder - Thank you for your response. Much appreciated.

Yes. Deposit before start of work was £3500. Second payment was £1000. So therefore, total payment so far is £4500.

Hi all, I will try and make this as brief as possible. I am currently getting a brick porch built it is 2/3 built. The price was agreed before building work commenced at £5,700. During the build i changed the plans for the roof before work on the roof had started, from a pitched roof to an hipped roof. I requested the extra cost for the roof on 6th August but did not receive the updated cost until work on the roof was close to completion. After several requests for for the amended price, i finally received an updated price on the 31st August. The final price of the build on the 31.08.19 is now £10,000. The additional cost of the hipped roof was £1,400 . However in the exchange of emails the builder has ACCEPTED liability that he miscalculated the size of the porch by adding the length and depth of the porch instead of multiplying. Therefore, this means that the materials for the bricks, cement, footings and labour for all ground works and brick layering, have all been miscalculated by in the builders quote. Subsequently, in the last 48 hours, i have now had 5 different quotes off him. 1 - 10,000 2 - 8,900 3 - 11,000 4 - 9,100 5 - 8,300 I have rejected all of these, as i do think i should be liable to pay for his incompetence regards to miscalculating the size of the build. I asked him the question if i had not changed the plan for the roof and the porch was built as planned with a pitched roof for £5,700, would you now be asking me for more money. His reply was yes due to miscalculating the size. For a quick solution i offered £7,500 for the completed build which i believe is reasonable but he has rejected this but would accept £8,300. Estimated build time was 2 weeks, we are now into the 9th week. I believe i am in my right to stand firm as he as accepted liability. Any feedback would be appreciated. Thanks