Where I live timber frame constaruction is expensive when done right so I have no idea what your architect is talking about. I think he is talking about wood instaed of masonary which is probably what he means where you live.

Saving money with timber framing? This is the most out-of-touch architect I've ever heard of. Hundreds of guys can stick frame; common as dirt. You're lucky if you've got two timber framers within driving distance.

Is this in the UK or maybe Canada? Doesn't look like a US house style.

hello @chispa - we are in the UK, in the east midlands. we are looking to make the dormer flush with the wall downstairs, therefore increasing the floor space upstairs.

hello @Patricia Colwell Consulting and @Joseph Corlett, LLC. Thanks for the reply. Apparently the reduction in labor creates cost savings. Apparently laying bricks on site takes more time than installing the timber frame. Additionally (so he says) the lighter frame compared to block work reduces the loading on the downstairs (which will also be extended outwards) and therefore requires steel beams with a less onerous specification. Do you think that's not quite right?

I am also really curious if a valuation with a traditional brick build will be higher / lower / the same as one with a timber frame construction

Building terms are different between the US/Canada and the UK. Hence, the misunderstanding. In this case, I think bkafwembe is referencing timber to be synonymous with lumber.

bkafwembe, Timber framing is the use of a network of large spans of large wooden beams to support a structure. You see these in your Tudor cottages in the south of England. Modern timber framing is extraordinarily expensive and typically only seen in very high end residential building. These timber frames are usually exposed.

There are some truisms between the nations. It would be less expensive in the long run to purchase a new home with additional space than attempt a renovation of the sort you are proposing. I think you will be disappointed by the amount of usable living space the renovation will provide versus selecting a bigger home.

To extend the dormer to the rear wall will require extensive improvements to the foundation, rear wall and roofing in order to carry the new load.

Fixed cost contracts are not common in the US/Canada. They seem to be more common in the UK. You need to discuss the costs of the project with your architect and site supervisor. It won't be easy or cheap.