Pro Calculator

Commercial → Residential Conversion Calculator

A full development appraisal — acquisition, planning, conversion, holding, GDV, refinance, tax and sensitivity analysis, with a per-unit breakdown.

Executive Summary

Total Investment Required (£):

£0.00

Gross Development Value (£):

£0.00

Total Development Costs (£):

£0.00

Development Profit (£):

£0.00

Profit on Cost (%):

0.00%

Return on Investment (%):

0.00%

Rental Option - Annual Net Income (£):
£0.00
Rental Option - Yield on Cost (%):
0.00%
Money Left in Deal After Refinance (£):
£0.00

Cost Breakdown

Project Timeline

Hide:

Module 1: Property Checks & Planning

Property Details

Property Address:

Current Property Type:

Current Use Class:

Building Area (sqm):

Estimated Convertible Area (sqm):

Number of Potential Units:

Planning Considerations

Prior Approval Status:

Permitted Development Rights:

Article 4 Direction in Place:

Listed Building Status:

Conservation Area:

Flood Risk Zone:

Local Authority Factors

Community Infrastructure Levy:

CIL Rate (£/sqm if applicable):

Section 106 Requirements:

S106 Estimated Cost (£):

Affordable Housing Requirement:

Affordable Housing % (if applicable):

Planning Application Fees (£):

Risk Assessment

Planning Risk Rating:

Not assessed

Technical Risk Rating:

Not assessed

Financial Risk Rating:

Not assessed

Module 2: Acquisition Costs

Purchase Costs

Purchase Price (£):

Stamp Duty Land Tax (£):

Legal Fees (£):

Survey Costs (£):

Agent Fees (£):

Search Fees (£):

Land Registry Fees (£):

Initial Finance

Funding Method:

Loan to Value (%):

Interest Rate (% p.a.):

Arrangement Fee (£):

Broker Fee (£):

Valuation Fee (£):

Acquisition Summary

Total Acquisition Costs (£):

£0.00

Deposit Required (£):

£0.00

Initial Finance Costs (£):

£0.00

Initial Equity Investment (£):

£0.00

Module 3: Conversion Costs

Professional Fees

Architectural Fees (£):

Structural Engineer (£):

Quantity Surveyor (£):

Project Management (£):

Building Control Fees (£):

Other Consultants (£):

Construction Costs

Construction Quality Level:

Custom Rate (£/sqm if selected):

Structure & External Works (£):

Internal Subdivision/Walls (£):

M&E Installation (£):

Plumbing & Heating (£):

Fire Safety Systems (£):

Windows & Doors (£):

Wall/Floor/Ceiling Finishes (£):

Kitchens & Bathrooms (£):

External Works & Landscaping (£):

Contingency

Contingency Percentage (%):

Contingency Amount (£):

£0.00

Conversion Summary

Total Professional Fees (£):

£0.00

Total Construction Cost (£):

£0.00

Total Conversion Cost incl. Contingency (£):

£0.00

Cost per sqm of Development (£):

£0.00

Module 4: Holding Costs

Project Timeline

Planning & Design Phase (months):

Construction Phase (months):

Sales/Letting Period (months):

Total Project Duration (months):

Monthly Carrying Costs

Business Rates (£/month):

Insurance (£/month):

Security (£/month):

Utilities (£/month):

Site Supervision (£/month):

Holding Summary

Monthly Holding Costs (£):

£0.00

Total Holding Costs (£):

£0.00

Finance Costs During Development (£):

£0.00

Total Holding & Finance Costs (£):

£0.00

Module 5: End Valuation & Revenue

Unit Breakdown

Sales Valuation

Average Unit Size (sqm):

Local Value per sqm (£):

Sales Agent Fee (%):

Sales Legal Fees (£):

Gross Development Value (£):

£0.00

Sales Costs (£):

£0.00

Net Proceeds from Sale (£):

£0.00

Rental Valuation

Average Rent per Unit PCM (£):

Estimated Occupancy Rate (%):

Management Fee (%):

Maintenance Reserve (%):

Gross Annual Rental Income (£):

£0.00

Net Annual Rental Income (£):

£0.00

Estimated Yield on Cost (%):

0.00%

Estimated Yield on GDV (%):

0.00%

Module 6: Finance & Refinancing

Development Exit Finance

Exit Strategy:

Refinance LTV (%):

Refinance Interest Rate (% p.a.):

Mortgage Term (years):

Mortgage Type:

Refinance Arrangement Fee (£):

Cash Flow Analysis

Refinance Amount (£):

£0.00

Monthly Mortgage Payment (£):

£0.00

Money Released on Refinance (£):

£0.00

Money Left in Deal (£):

£0.00

Monthly Net Cash Flow (£):

£0.00

Annual Net Cash Flow (£):

£0.00

Module 7: Tax & Analysis

Tax Considerations

Ownership Structure:

Corporation Tax Rate (%):

VAT Option to Tax:

ATED Applicable:

Estimated Corporation Tax (£):

£0.00

Profit After Tax (£):

£0.00

Performance Metrics

Total Development Costs (£):

£0.00

Development Profit (£):

£0.00

Profit on Cost (%):

0.00%

Profit on GDV (%):

0.00%

Return on Investment (%):

0.00%

Return on Capital Employed (%):

0.00%

Sensitivity Analysis

Cost Overrun Scenario:

Value Change Scenario:

Timeline Extension:

Adjusted Development Profit (£):

£0.00

Adjusted Profit on Cost (%):

0.00%

Adjusted ROI (%):

0.00%

Converting a commercial building into flats is a development appraisal, not a purchase calculation. This tool prices the scheme per unit, builds the gross development value and shows whether the numbers survive a fall in end values.

What this calculator works out

Per-unit build costs, professional fees, planning and building control across the whole scheme.
Gross development value from the individual unit values, not a single headline figure.
Development finance with staged drawdowns, rolled-up interest and exit costs.
Refinance or sale at completion, and the profit on cost that results.
Sensitivity analysis: what a 5% or 10% fall in end values does to the profit.

How the result is worked out

Gross development value (GDV) is the sum of the end values of every completed unit. Total development cost adds the acquisition costs, the full conversion cost including professional and planning fees and the contingency, and the holding and finance costs. Development profit is GDV less total development cost, taken before sales costs and corporation tax. Profit on cost is that profit divided by the total development cost; profit on GDV divides the same profit by GDV instead. The sensitivity view reruns profit on cost at lower end values.

A worked example

A £280,000 commercial building converted into four flats at £150,000 of build cost each carries roughly £900,000 of total cost with fees and finance. At £275,000 a flat the gross development value is £1.1m — a 22% profit on cost that turns into 11% if values slip 5%.

Common questions

Do I need planning permission to convert commercial to residential?

Many conversions from commercial use to dwellings proceed under permitted development with a prior approval application rather than a full application, but the rights are conditional and vary by use class and location. Confirm the position for the specific building before you appraise it.

What profit on cost do developers target?

Twenty per cent on cost is the usual benchmark, and lenders often expect it before they will fund. It exists to absorb build overruns and a softer sales market, not to be handed back in the purchase price.

What is the biggest risk in a conversion?

The end value. Build costs can be tendered and fixed; sales values cannot. Run the appraisal at values below today’s comparables and see whether the scheme still works.

Related tools and services

Worth running the same deal through the Buy-to-Let Calculator and the HMO Calculator before you commit to a strategy — the same building can look very different under each, and the gap between them is usually the real decision. The rest are in the calculator library.

If the numbers work and the property is in Liverpool or the Wirral, we run it for a living: see HMO and BTL management for a property you already own, or investment sourcing if you are still looking for the right one.

Want this run on a real deal with you? Come to the free class, or take the whole set in the UK Property Investor Toolkit.

Commercial → Residential Conversion Calculator

Commercial to Residential Conversion Calculator

Executive Summary

Cost Breakdown

Project Timeline

Module 1: Property Checks & Planning

Property Details

Planning Considerations

Local Authority Factors

Risk Assessment

Module 2: Acquisition Costs

Purchase Costs

Initial Finance

Acquisition Summary

Module 3: Conversion Costs

Professional Fees

Construction Costs

Contingency

Conversion Summary

Module 4: Holding Costs

Project Timeline

Monthly Carrying Costs

Holding Summary

Module 5: End Valuation & Revenue

Unit Breakdown

Sales Valuation

Rental Valuation

Module 6: Finance & Refinancing

Development Exit Finance

Cash Flow Analysis

Module 7: Tax & Analysis

Tax Considerations

Performance Metrics

Sensitivity Analysis

Email me this analysis

What this calculator works out

How the result is worked out

A worked example

Common questions

Do I need planning permission to convert commercial to residential?

What profit on cost do developers target?

What is the biggest risk in a conversion?

Related tools and services