Best construction method for our self build

jimmyharris80 · March 18, 2022

Hi all,

I’ve posted over on the ‘Introduce Yourself’ thread so apologies for any repetition here, I think this here is the best forum for this particular post.

A bit of background in terms of our journey so far…my wife and I are embarking on a self build project in Hertfordshire for our family of four. We are complete novices to the selfbuild game, have done a fair bit of reading to educate ourselves but it’s a steep learning curve, we have mostly been led by our architect to date. Really glad to have stumbled upon this great resource, just wish I’d found it sooner!

We currently have a bungalow on site with an adjoining garage, the property has had a number of hotch potch extensions over the years. We’ll be knocking this down in 2 stages to make way for our new build. We plan to stay on site during the build in the main bungalow, demolishing the garage and back bedroom flat roof section to make way for the new dwelling. Then moving across and demolishing the bungalow to make way for the garage, here is the site plan where you can see (just!) the outline of the existing dwelling and where the new one will be sighted:

We have been through the design process with our architect over the past 12 months and have planning approval for a design that we love (you can see some 3Ds on my intro posts here) , it’s now about putting this into practice, which is where we are now feeling the struggle a little with some differing opinions on our construction method.

When we first embarked on the project the plan was to go with a timber frame construction, mainly due to the flexibility it offered, eco credentials and speed of construction on site once we're out of the ground. As the design has developed, due to the sloping nature of the site and existing drive entrance and property level we now have a ground floor / semi-basement that will also form a retaining wall. The proposal at the moment is for this ground floor to be built in blockwork and rendered, with timber frame at 1st and 2nd floor levels, our building regs design docs have been produced with that as the assumption to date.

We have made initial contact with a couple of main contractors who have questioned timber frame as a build approach and have suggested blockwork up to the roof level maybe a better and more cost efficient way forward, so a continuation of blockwork from the ground floor level up to the roof.

The other thing that has been mentioned is that timber cladding on timber frame (which would be the case on the 1^st/2^nd floor) could be problematic in terms of future mortgage or insurance policies. This has made us question a little whether we are still heading in the right direction in terms of build method.

We are now at the stage where we need to instruct a structural engineer to design the foundations, retaining walls and drainage for building regs, our construction method will have a bearing on this in terms of loading so we want ensure we go with the right build approach for our circumstances.

Below are our elevations and sectional drawing to give you an idea of what we’re looking to achieve, I welcome any feedback. The advice we’ve been given to date is to design, design, design to ensure that any uncertainty and future changes are kept to an absolute minimum, so we are taking our time at this stage to ensure we are setup for success.

Any input or reassurance you guys could offer at this stage would be hugely appreciated!

Elevations: