How much should a builder spend on Google Ads? (UK)
Short answer
There's no fixed figure that works for every builder. Work out what one enquiry is worth to you from your own job value and margin, then spend up to that amount to win it, building your budget from there.
How much should a builder spend on Google Ads?
There's no number that works for every builder, and anyone who gives you one without asking about your jobs is guessing. What you should spend comes from working out what one enquiry is worth to you, using your own job value, not from what another trade spends.
For a mansard loft conversion firm, that number is usually bigger than most builders assume, simply because the job itself is bigger. Work it out properly below, and build your budget up from there, not from a figure you saw mentioned on a forum.
Spend too little and you won't show up often enough against other loft firms bidding for the same searches. Spend without checking your numbers first, and you can burn through profit on jobs you haven't even won yet.
Work out what one enquiry is worth to you
Start with your own numbers, not a generic rule. Here's what you need:
- Your average job value
- Your margin (what's left as profit once materials, labour and overheads are paid: check with your accountant if you're not sure of your own figure)
- Roughly what share of survey visits turn into a signed job
Say your mansard loft job is worth £70,000, and your margin is 30 percent. That's £21,000 profit on the job (£70,000 x 0.3). Say half the survey visits you do turn into a signed job: that means each survey visit is worth around £10,500 in profit to you, on average (£21,000 divided by 2).
That number is your ceiling, not a target. It's the most you could justify spending, across ads and your time, to win one survey visit, and most of what you actually spend should sit well under it.
Set a monthly budget from your diary, not a guess
Once you know what a survey visit is worth, work backwards from how many extra jobs you actually want.
Say you want one extra mansard loft job a quarter. If roughly half the surveys you run convert, you need two extra survey visits every three months to get there. Say you want two extra jobs a quarter: you need four extra survey visits over that period, a bit more than one a month.
Multiply that number of survey visits by what each one is worth to you, from the sum above, and you've got a sensible top end for what Google Ads could cost you to deliver them. Start a chunk under that, watch what happens for a month, and adjust rather than committing a full quarter's spend on day one.
Set your locations and times so you're not paying for the wrong clicks
Loft conversions are local work: nobody books a mansard loft from two hundred miles away. In Google Ads, under Locations, choose the setting that shows ads to people in or regularly in your targeted locations, not the default, which can also show your ad to people simply searching about your area from anywhere in the country.
Set a radius that matches how far you'll actually travel for a job, and check it against your last dozen real addresses rather than guessing. A radius that's too wide wastes budget on homeowners who'd never book a firm an hour and a half away, and too narrow misses the villages just outside town full of exactly the roofs you convert.
Enquiries for loft conversions tend to rise in January and February, and again from September into October, as families plan space for the year ahead. If your budget is tight, weight more of it towards those months rather than spreading it evenly all year.
Match your ads and landing page to how people search for loft conversions
Homeowners researching a mansard loft rarely search the same way twice. Build your keyword list around the actual phrases people type, such as mansard loft conversion cost, loft conversion company near me, and do I need planning permission for a loft conversion.
Add negative keywords so you stop paying for clicks that were never going to book a survey: terms like loft ladder, loft insulation, loft storage, and diy loft conversion are all worth excluding from day one.
Send the click to a page about mansard loft conversions specifically, with a form or a number to call, rather than your homepage. A homeowner who clicked an ad about a mansard loft and lands on a generic about us page will usually just leave.
Track what happens after the click, not just the click itself
A click tells you almost nothing on its own. Set up conversion tracking so you can see which keywords and ads actually produce a phone call, a form fill or a booked survey, not just a visit to the page.
A simple way to do this without extra kit: use a separate phone number on your ads landing page just for Google Ads traffic, so you can see on your phone bill or call log which enquiries actually came from the ad.
Check this weekly for the first month, then monthly once you've got a few weeks of data. Pause or rewrite the keywords that get clicks but never a call.
Review monthly, and decide whether to scale up, dial back, or pause
Once you've got a month or two of real numbers, compare what each survey visit actually cost you to the ceiling you worked out earlier.
If the real cost sits comfortably under your ceiling, that's a sign the budget is working, and it may be worth testing a bit more spend to see if you get proportionally more surveys. If it sits above your ceiling, look first at your keywords and negative keywords before you touch the overall budget, because the issue is usually who you're reaching, not how much you're spending.
If you genuinely cannot get the cost under your ceiling after a proper look at keywords, location and the landing page, it's fair to pause and try a different approach instead. Planning questions and surveys already eat enough of your evenings without a Google Ads account you don't trust doing the same.
Google Ads for a trade like loft conversions isn't about matching what the builder down the road spends. It's about knowing what one enquiry is worth to you, and being disciplined about staying under that number while you learn what actually works.
Questions people ask
How much should a builder spend on Google Ads?
There's no fixed figure that applies to every trade. Work out what a survey visit or enquiry is worth to you from your own job value and margin, then build a budget that sits comfortably under that number.
Is Google Ads worth it for a small loft conversion firm?
It can be, because loft conversions are high value jobs and homeowners actively search online while planning one. Whether it's worth it for you depends on how quickly you can answer and chase enquiries, since a slow response often loses the job before the ad has done its work.
How do I know if my Google Ads budget is working?
Track what happens after the click, not just the click itself, by setting up conversion tracking so you can see which keywords actually produce a phone call or a booked survey. Compare the real cost of each survey visit to the ceiling you worked out from your own job value.
Should I pause Google Ads over winter?
Enquiries for loft conversions tend to pick up in January and February and again from September into October, so those are good months to weight more budget towards rather than pausing completely. Keeping some presence running year round means you're still visible when someone decides to start planning.
Do I need a dedicated landing page for Google Ads?
Yes, ideally. Sending clicks to a page specifically about loft conversions, with a clear way to get in touch, converts better than sending them to your homepage or a generic contact page.
Do it yourself, or hand it over
Imagine one extra dormer loft a month at £45k: that's £540,000 over a year chasing quotes yourself. Or we chase every quote to a yes or no, show every lead in your login, and you stay on the tools. Book the free 20-minute call with Ben or Sam and we'll tell you straight if we can help.
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