Orangery and new kitchen - how to start?

[twolittleboysonetiredmum]

I’m at a loss so hoping someone can help!
We need to price up if we can afford to knock a small dining room and kitchen together and remove a conservatory to replace with an orangery that would join to our garage - currently a separate external door we get to via conservatory.
Where do we start?! I’ve no idea who to ask as we want to do a kitchen, building work and move a boiler (is in kitchen currently and needs replacing and moving somewhere else as is not compliant)

An architect can design everything for you. They can get quotes and advise on building materials and likely costs. Start with them. Or try a builder but if you need plans and building regs, I would pay a professional.

Thanks - how would we know if we need planning permission etc?

Have a look on the planning portal , that will tell you if you need PP.