Write a service page

I work in marketing at a construction firm. Help me write a web page for one of our services.

Context: Commercial buyers scan for sectors, project sizes and accreditations before they shortlist. Homeowners look for who turns up, how long the work takes and what protection they have if something goes wrong.

Before you start, ask me for anything missing from this list:
- The service and who it is for
- What happens, step by step
- How we charge
- What we cannot promise

Then:
1. Open with who this is for and the problem it solves.
2. Explain what happens in order, in plain words.
3. Explain cost or how pricing works.
4. Answer the five questions people ask before getting in touch.

Give me:
- A headline and a one-line summary
- The page, 400 to 600 words, with question headings
- One call to action

Rules:
- Use only the facts I give you. Where something is missing, write [detail needed]. Never invent a number, a name, a quote or a source.
- Describe building work in general terms only. Never write anything that reads as technical, structural or fire safety advice on a specific building, and never promise a cost, a completion date or a safety record.
- Write in plain English, in our voice if I have given you a sample.
- Do not tell me what the rules or regulations say. If something may be restricted, flag it and I will check.

Finish with a list headed "Check before this goes out". Include these, plus anything else the director who approves marketing or our health, safety and quality lead should see:
- Accreditations and scheme memberships named correctly and currently held
- Warranty or guarantee wording, against the document the customer receives
- Project value ranges and timescales quoted on the page