Innovation13 min read
Real estate digital twin and 2D/3D plans: what they really do for a portfolio
Real estate digital twin: what it contains, how to capture 2D/3D plans during a visit and how it helps you relet, plan works and decide.
The homePad team
A real estate digital twin is the digital copy of a property: its plans, its floor areas, its rooms, its equipment, their condition and the history of what has happened there. For an asset manager, it serves to answer practical questions without travelling: how many square metres to relet, which homes to refurbish first, what works budget to plan over three years. 2D/3D plans form its foundation. The findings made at each visit keep it up to date.
What is a real estate digital twin, in practice?
A digital twin is a representation of a real property, structured as data and kept up to date throughout its life. The term brings to mind a spectacular 3D model. For a property manager, the value lies above all in the information attached to each room and each piece of equipment, and in keeping it up to date.
A BIM model (Building Information Modelling) is the digital model produced by architects and engineering firms to design and construct a building. It rarely exists for an older portfolio and rarely lives on after handover. A property manager's digital twin starts from what already exists, captured during visits.
A 2D plan is the top-down view of a home, room by room, with its dimensions. A 3D plan adds the heights and the volume.
What does a real estate digital twin contain?
A useful digital twin brings together six families of data, each attached to the right level: building, unit, room or element.
| Data | Level | Where it comes from | What it is used for |
|---|---|---|---|
| 2D/3D plans and floor areas | unit, room | captured on site | reletting, checking floor areas, works quantities |
| Rooms and ancillary areas | unit | plan, inspection report | shared structure for visits |
| Equipment | room | inspection report, inventory, technical visit | maintenance, replacement |
| Condition of each element | element | dated, photographed findings | tracking wear, priorities |
| Visit history | unit, building | signed reports | evidence, change over time |
| Works noted and carried out | unit, building | works reports, repairs | budget, planning |
The decisive point is vocabulary. If a room is called "living room" in one report and "lounge" in the next, or if the condition of a floor switches from a four-level scale to a free-text comment, the data can no longer be compared. A digital twin is first and foremost a data-entry discipline.
What is a real estate digital twin used for in asset management?
The digital twin serves to decide faster and on the basis of facts, without sending someone on site for every question. Six uses come up again and again.
Reletting. A clear 2D plan helps the applicant picture themselves in the home and limits mistakes in the listing. Together with the last move-out inspection report, it shows straight away whether the home can be relet as it is.
Checking floor areas. A measured plan reveals the differences between your files and the unit, before a tenant or a buyer discovers them. It does not replace a measurement made according to your country's rules where one is required.
The lease states the habitable floor area (art. 3 of law no. 89-462 of 6 July 1989): the floor area minus walls, partitions, stairs, ducts and window and door recesses, excluding cellars, garages, balconies, loggias and parts less than 1.80 m high (art. R156-1 of the Construction and Housing Code). If the actual area is more than one twentieth smaller, the tenant can ask for a proportional rent reduction (art. 3-1). For the sale of a unit in a co-ownership building, it is the "Carrez law" floor area (art. 46 of law no. 65-557 of 10 July 1965). Using a professional for this measurement is not mandatory, but it is advisable when the unit is complex.
No federal rule sets how a rented home is to be measured or requires its floor area to be stated in the lease; professional standards, such as the SIA 416 standard of the Swiss Society of Engineers and Architects, define floor areas: state in the lease which method was applied. If an advertised floor area was decisive and turns out to be significantly smaller, the Federal Supreme Court accepts a fundamental error (art. 24 para. 1 no. 4 CO) and the rent is brought down to the actual area (ATF 135 III 537, commercial premises, a difference of almost 17%); the same judgment recalls that a difference of more than 10% has been held unacceptable in any case (judgment 4C.5/2001).
In Brussels, since 1 November 2024, the landlord discloses the habitable floor area before signing (art. 217 of the Brussels Housing Code), and it is used for registering the lease and for the reference rent grid. In Wallonia (art. 3 of the decree of 15 March 2018) and in Flanders (art. 8 of the Woninghuurdecreet), the floor area is not among the mandatory particulars of the lease.
The national ILNAS 101:2016 "Habitable floor area" standard harmonises the calculation rules, with a margin of error of 5% at most. The mandatory particulars of the lease (art. 5(1) of the amended law of 21 September 2006, reformed by the law of 23 July 2024) do not include the floor area.
Planning works. The dimensions on a plan give quantities for costing paintwork or a floor covering. The works noted at each visit form an up-to-date list, unit by unit.
Prioritising investment. Cross-referencing the condition of equipment, its age and the works noted ranks the units: what must be done this year, what can wait. This is the raw material of a multi-year works plan and, for a social housing landlord, of its asset strategy.
Making asset decisions. Keeping, renovating or selling an asset is easier to decide when the cost of upcoming works is known unit by unit rather than estimated at an average per square metre.
Preparing energy renovation. The official energy certificate remains the job of an accredited expert. The twin supplies them with plans, floor areas and the condition of heating equipment and windows and doors, and helps group works by building, ahead of the deadlines set by each country.
The energy performance certificate (DPE) is drawn up by a certified assessor. The Climate and Resilience law of 22 August 2021 is gradually banning the letting of the most energy-intensive homes, which become substandard (art. 6 of the law of 6 July 1989): class G since 1 January 2025, F from 1 January 2028, E from 1 January 2034 in mainland France, for leases signed, renewed or tacitly renewed from those dates. The bill on reviving and decentralising housing, examined by Parliament in 2026, touches on these rules: check the text in force when you decide. Social housing organisations (HLM) schedule these works in their strategic asset plan (art. L411-9 of the Construction and Housing Code), which analyses the quality of the stock and sets the resulting investment choices.
Measures on energy in buildings are primarily a matter for the cantons (art. 89 para. 4 of the Federal Constitution); no federal rule bans letting an energy-intensive home. The cantonal building energy certificate (CECB) is mandatory on sale in Fribourg (art. 11a of the cantonal energy law) and in the canton of Vaud since 1 January 2017, including when a fossil-fuel heating system is replaced; in Neuchâtel, for large buildings built before 1990, it is provided on sale and on letting (art. 45 and 49 LCEn). In Geneva, the heat expenditure index (IDC) is calculated every year and requires works above 800 MJ/m² per year until 31 December 2026, 650 from 2027, 550 from 2031. In other cantons, check with the cantonal energy department.
A PEB certificate (Brussels, Wallonia) or EPC (Flanders) is mandatory to sell or let, and its indicators appear in listings. Brussels: no rent indexation without a registered lease and a PEB certificate given to the tenant; every home will have to reach at least 275 kWh/m² per year by 1 January 2033 (RENOLUTION ordinance of 7 March 2024), and the certificate requirement is to be extended to all homes, including owner-occupied ones. Wallonia: PEB date and rating in the lease (art. 3 of the decree of 15 March 2018). Flanders: a home acquired since 1 January 2023 with an E or F label must reach at least label D within a period that runs from the authentic deed: check on vlaanderen.be which period applies to the date of the deed.
The energy performance certificate, known as the energy passport, is mandatory on sale and at each change of tenant if there is no valid one; a copy is given to the new tenant and the energy and insulation classes appear in listings (art. 14 and 17 of the amended grand-ducal regulation of 9 June 2021). It is valid for 10 years (art. 18). No letting ban is linked to the energy class.
How do you capture a 2D/3D plan during a visit?
The plan is captured on site, room by room, with a tablet or a smartphone, during a visit that is already scheduled. The best moment is the inspection report: the home is empty and the condition of each element is recorded on the same visit. Our guide to digital inspection reports details the method.
- Choose an empty home where possible: a piece of furniture against a wall hides a corner and distorts the outline.
- Open the interior doors and light each room.
- Capture the rooms in the same order and under the same names as the inspection report.
- Include the ancillary areas: cellar, balcony, loggia, storeroom, parking space.
- Check the plan before leaving: number of rooms, openings, total floor area compared with the one in your file.
- Attach the plan to the unit and the building so that it joins the history.
The most common mistake: handing the plans over to a separate campaign, with different room names. The plan and the inspection report no longer match, and the portfolio has two versions of the truth.
How does the data feed the dashboards?
Each visit produces structured data (floor areas, rooms, elements, conditions, works) which, once aggregated, becomes portfolio indicators:
- floor area captured per building, compared with the declared floor area
- number of units with an element rated damaged, by type of element
- estimated amount of the works noted, per building and per year
- date of the last inspection report or the last technical visit of each unit
- map of the units to renovate
These indicators are only worth something if the data is entered the same way everywhere and can leave the tool, by export or API, for your management software. As our article on AI in property management points out, a digital twin first requires reliable data.
Where to start: a pilot on one building
Start with one building, one question and a few months. A good pilot answers a real decision: "which homes in this building should be renovated before they are next relet?"
- Choose a representative building, with turnovers coming up.
- Write down the pilot's question and the indicator that will answer it.
- Settle the shared structure: room names, elements, condition scale.
- Bring in the history: old reports, known floor areas, past works.
- Capture the plans during scheduled visits, without dedicated trips.
- Take stock: time spent, missing data, decision taken.
If the pilot leads to no decision, the cause almost always lies in the question asked or in data-entry discipline, rarely in the technology.
What are the limits of a digital twin?
A digital twin is only as good as how up to date its data is. A plan captured before two rooms were knocked into one will mislead for years: decide who updates what after works.
- It replaces neither mandatory surveys nor a binding measurement.
- An occupied home is hard to capture, and only with the occupant's agreement, whose photos are personal data (see our GDPR checklist).
- A home only becomes vacant when its tenant leaves, so covering a portfolio through turnovers alone takes years. Technical building visits speed up the capture.
- The link with your other software depends on its vendor's API.
What homePad does for you
homePad captures plans during the visits your teams already carry out, then brings this data together across the portfolio. Since 2013, more than 10,000 professionals have used it every day.
- homePad App captures measured 2D/3D plans on a tablet or smartphone, during an inspection report or a technical building visit.
- The Pro plan includes 10 free 2D/3D plans and unlimited, configurable templates.
- Time-stamped, geolocated photos; the built-in AI detects defects, drafts the works report and estimates costs, and the professional approves.
- homePad One brings together dashboards, KPIs, property mapping, the digital twin, data export, an open API to management software and the import of historical data.
- See the uses for real estate investment companies and social housing landlords.
Frequently asked questions
What is the difference between BIM and a digital twin?
The BIM model is the digital model created to design and construct a building, highly detailed on the structure and the networks. The digital twin is used for operations: it describes the property as it is today and is enriched at every visit. A BIM model can serve as a starting point, but most older portfolios do not have one.
How do you make a 2D floor plan of a flat with a smartphone?
Use a capture app that records the plan room by room, preferably in an empty home, with the doors open and the rooms lit. Capture the rooms in the same order and under the same names as your inspection reports. Before leaving, compare the floor area obtained with the one in your file.
Is a smartphone floor plan as good as an official measurement?
No. A plan captured during a visit serves to describe the property and to spot differences in floor area. It does not replace a measurement made according to your country's rules where one is required (see the box on floor areas). If there is a significant difference, have the unit measured before changing a lease or a listing.
Do you need a digital twin of the whole portfolio from day one?
No. Start with one building and one precise decision, with a shared data-entry structure. Then extend it as turnovers and technical visits come round, once the method has proved itself.
Can a digital twin help with energy renovation?
It replaces neither the official energy certificate nor the audit, carried out by an accredited expert (see the box on energy). It supplies them with plans, floor areas and the condition of heating equipment and windows and doors. It also helps group works by building and include them in a multi-year plan.
Who keeps a real estate digital twin up to date?
The person who carries out the visit updates the field data: condition, equipment, the plan if the unit has changed. After works, the property manager who closes them updates the unit concerned. Without this written rule, the data ages and loses its value.
- real estate digital twin
- 2D/3D floor plans
- floor area
- asset management