Replacing Old Loft Hatch

[Terry34673]

I want to replace the old loft hatch in our house because it's not well insulated, looks bad etc. Basically it's just a thin bit of old wood. I looked at a pre-built new plastic loft hatch in B&Q but unfortunately I think the structural opening is too small for it. Also, there is a raised wooden frame around the opening that is not flush with the ceiling. Where could I get a correctly sized pre-built loft hatch from, and how would I fit it/would I need to remove the raised wooden frame? Thank you !

https://drive.google.com/file/d/1FwtT5vDyfkkPSqrmRd9HIX9JDeRoPLxs/view?usp=sharing

https://drive.google.com/file/d/1p85lV2eP6zNQg22uQPGQrf8nEFIQ0eAc/view?usp=sharing

 

[foxhole]

But closest size available and modify hatch opening , the trim should pry off easily .
Or take the opertunity to open up to take a larger hatch and make access easier .