Stamp Duty CalculatorHouse Buying Budget Planner
A nine-category framework for building a defensible UK home buying budget — before you start viewings.
A house-buying budget isn't just "the deposit plus some". It's nine categories of spending — five upfront, three ongoing, one contingency — checked against affordability before you commit. This planner walks the framework with worked numbers and the common places people get caught out.
The nine categories — at a glance
| # | Category | When | Typical range |
|---|---|---|---|
| 1 | Deposit | Saved over months/years; released exchange + completion | 5–25% of price |
| 2 | Stamp duty (SDLT) | Within 14 days of completion | £0 (FTB ≤£300k) to £20k+ |
| 3 | Conveyancing & disbursements | Mostly at completion | £1,200–£3,000 |
| 4 | Survey & valuation | Before exchange | £300–£1,800 |
| 5 | Mortgage product & arrangement fees | Application or completion | £0–£2,000 |
| 6 | Removals & immediate post-move | Around completion | £800–£3,500 |
| 7 | Monthly mortgage | Month after completion onwards | 4.5% of loan/year typical |
| 8 | Ongoing home running costs | From completion onwards | £400–£700/month |
| 9 | Contingency & maintenance reserve | Always | 1–2% of price + 1%/year |
Step 1 — Set your affordable price ceiling
The wrong way to budget is to start from "what property do I want" and work backward. The right way: start from what mortgage you can reliably afford and add your deposit to set the price.
Use the affordability calculator to get your borrowing range at conservative (4×), standard (4.5×) and stretch (5×) multiples. Pick the standard scenario as the baseline — stretching to 5× leaves no headroom for rate rises.
Worked example for a household on £50,000 combined gross income with £200/month of debt commitments:
- 4.5× household income: £225,000 headline
- Less debt adjustment (£200 × 40): −£8,000
- Max sensible mortgage: £217,000
- Plus £25,000 deposit (10%): Max property price ~£242,000
Step 2 — Budget the deposit
Decide your target LTV before the price is fixed. 15% deposit is the sweet spot for first-time buyers; 25% gets you the best rates. Use the deposit calculator for the figure at each LTV, and the deposit savings calculator to model the savings timeline.
If you're 18–39 and a first-time buyer, the LISA bonus typically shaves 6–12 months off the timeline.
Step 3 — Add the upfront costs
Build the upfront-cash total from the same four calculations every time:
| Cost | Typical | Where to get exact figure |
|---|---|---|
| Deposit | 5–25% of price | Deposit calculator |
| Stamp duty (SDLT) | Variable by buyer type | Main SDLT calculator |
| Conveyancing | £1,200–£3,000 | Conveyancing calculator |
| Survey | £300–£1,800 | Quotes via RICS |
| Searches, Land Registry, CHAPS | £475–£855 | Conveyancer's disbursement list |
| Mortgage product + valuation | £0–£2,300 | Lender's product info |
| Removals | £800–£3,500 | Moving costs calculator |
| Buildings insurance (first year) | £220–£400 | Comparison quote |
| Post-move essentials | £500–£2,000 | Self-budgeted |
Or compute the total automatically using the home buying cost calculator — it sums every line above for any price + scenario.
Step 4 — Build the contingency
Two contingency pots, both worth keeping:
- Moving contingency: 1–2% of property price. Covers survey-triggered renegotiations, indemnity insurance, chain wobbles, post-completion surprises (locks, broken white goods, immediate small repairs).
- Annual maintenance reserve: ~1% of property value per year. £3,000/year on a £300,000 home. Reality: maintenance spend is lumpy — some years are £500, some are £8,000 (new boiler, roof patch, kitchen replacement). Saving the average each year smooths the cash flow.
See the hidden costs guide for the specific surprises the contingency is buffering against.
Step 5 — Project the ongoing monthly cost
Once you've calculated the upfront cash, model the monthly outgoing against your net income. The components:
- Mortgage payment (use the mortgage repayment calculator)
- Buildings insurance ~£23/month
- Council tax £150–£300/month by band
- Utilities £180–£280/month for a 3-bed
- Broadband + TV licence £40–£55/month combined
- Maintenance reserve £250–£500/month (~1% of property/year)
- Service charge + ground rent (leasehold only) — £100–£300/month typical for flats
On a typical UK 3-bed semi at £350,000 with a £315,000 mortgage at 4.5% over 25y, total monthly housing cost is roughly £2,400–£2,750 — of which the mortgage is only about £1,750. The rest is the often-overlooked half of homeownership.
Step 6 — Stress-test it
Two stress tests before you commit:
- Rate stress: what happens to the monthly mortgage at +1%, +2% and +3% above your assumed rate? Use the mortgage stress test calculator.
- Income stress: can you still cover the monthly housing cost on one income (if joint) or on 80% of current pay (if solo)? This catches redundancy and reduced-hour scenarios.
If either stress test puts the monthly above 50% of household net income, the budget needs revisiting — usually by reducing the target price.
Worked end-to-end budget — FTB, £50,000 household income
Scenario: First-time buyer couple, £50,000 combined gross income, 10% deposit, targeting a £242,000 home (max from Step 1).
| Category | Amount |
|---|---|
| 1. Deposit (10%) | £24,200 |
| 2. Stamp duty (FTB, ≤£300k → £0) | £0 |
| 3. Conveyancing | £1,200 |
| 4. HomeBuyer survey + valuation | £800 |
| 5. Mortgage product fee | £999 |
| 6. Searches, Land Registry, CHAPS | £475 |
| 7. Removals (local, 2-bed) | £650 |
| 8. First-year buildings insurance | £280 |
| 9. Post-move + 1% contingency | £2,420 |
| Total upfront cash | £31,024 |
Monthly housing cost projection (£218k mortgage at 4.5% / 25y):
- Mortgage: £1,212
- Buildings insurance: £23
- Council tax (Band C): ~£180
- Utilities (2-bed): £200
- Broadband + TV licence: £45
- Maintenance reserve: £200
- Total ongoing: ~£1,860/month
As a percentage of household net pay (~£3,170/month for £50,000 gross), that's 59% — close to the upper sustainable band. The budget works, but there's limited headroom for rate rises or unexpected expenses. Worth considering either a slightly lower price ceiling or an income/contribution uplift before committing.
Common planner mistakes
- Counting gross income instead of net. A £50,000 gross household earns roughly £3,170/month after tax and NI — not £4,170. Always plan housing cost against net.
- Forgetting council tax. Especially common for buyers moving from rented properties where the landlord paid it.
- Underestimating maintenance. The 1%/year rule isn't pessimistic — it's the actual average across UK owner-occupier surveys.
- No income stress test. Buyers often plan around current dual-income reality. A pause for one earner — parental leave, illness, redundancy — collapses the budget if it wasn't tested.
- Treating the survey as optional. A £700 survey that triggers a £5,000 price renegotiation is one of the best returns in the entire process.
Frequently asked questions
How do I plan a budget for buying a house?
Work from the property price downward. List the nine cost categories: deposit, stamp duty, conveyancing, survey, searches and Land Registry, mortgage product fees, removals, buildings insurance and post-move costs. Add a 1–2% contingency. Then check the monthly mortgage is comfortable against your net income before committing.
What's a sensible house-buying budget on £45,000 income?
At 4.5× household income, £45,000 supports roughly £202,500 of mortgage. With a 10% deposit (£22,500), that's a £225,000 property — putting you in the FTB SDLT zero-rate band. Total upfront cash needed (deposit + fees + contingency) is typically £27,000–£30,000 on this scenario.
Should I budget for ongoing monthly costs?
Yes. The mortgage is only one of the recurring costs. Buildings insurance (~£23/month), council tax (£150–£300/month by band), utilities (£180–£280/month for a 3-bed), broadband (£25–£40), TV licence (~£15) and a maintenance reserve (1% of property value per year, roughly £250–£500/month) all add up. The mortgage typically accounts for only 50–65% of total ongoing housing cost.
How much contingency should I include?
1–2% of the property price for the buying phase, plus 1% per year of property value as an annual maintenance reserve after move-in. On a £350,000 home that's £3,500–£7,000 of moving contingency and £3,500/year of maintenance budget.
Can I budget if I'm self-employed?
Yes, but the income side of the budget needs more care. Lenders typically assess self-employed applicants on 2–3 years of average net profit (sole trader) or salary plus dividends (limited company). Use the average rather than the most recent year, and keep a larger contingency — your borrowing range is more sensitive to lender choice.
When should I start the budget?
Ideally 12–18 months before you start viewings. That gives you time to build the deposit, establish clean banking patterns for the mortgage application, and refine the budget against real costs. Three months is the minimum useful planning window — anything shorter and you're reacting rather than planning.
Related calculators
Related guides
Verify your take-home pay assumption against your actual payslip via PayslipCheck. Self-employed income evidence is covered on Freelance Toolkit UK.
Sources
Last reviewed: 25 May 2026.