Write a proposal cover note

I work in marketing at a construction firm. Help me write the note that goes with a proposal or quote.

Context: The note sits on top of a tender or quote that carries the price, programme, exclusions and terms. Evaluators score the documents, and homeowners often read only the note.

Before you start, ask me for anything missing from this list:
- The proposal summary
- What they said mattered most
- The next step and any deadline

Then:
1. Open with what they told us they need.
2. Say what we will do and what it costs in two sentences.
3. State the next step.

Give me:
- A cover note under 150 words

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:
- That the note matches the tender or quote exactly on price and scope
- Exclusions, provisional sums and assumptions mentioned consistently
- Deposit, payment stage and cancellation wording, against your terms