Lantern Box.More home. Same land.
Before looking for another property, consider the potential of the current one you have. Lantern Box adds a new home above the one that already exists, carried on its own frame.
It starts as a one-storey loft that can be further developed into a two-storey, self-contained unit, while the house below stays in use. It works for a single home or across a portfolio of properties.
See it applied to a real house: Nepahwin 2.0, a Lantern Box in design above an occupied home in Sudbury.
- Existing
- Footings
- Frame
- Lantern Box
The old house does not carry the new one.
New columns and foundations carry the addition to the ground, so there is less structural work inside occupied rooms and the sequence is easier to control.
- New frame firstColumns and foundations go in along the outside of the house.
- Existing house stays intactThe addition touches the old structure as little as possible.
- Shell before fit-outAn enclosed shell, connected to the house, comes before interior work.
- Plan for changeFuture floors, access and services are designed for from the start.
Build the box, then fill it in.
Settle approvals, structure and the order of work before choosing the interior layout.
Site and foundations
Survey, setbacks, access, services and the first independent supports.
Frame and shell
Structure, weather protection and the connection to the existing house.
Loft fit-out
One storey with a kitchen, washroom, its own entrance and a tall living space.
Optional upper floor
The stair and service routes are already in place, so bedrooms, an office and a full bath can be added later.
The frame stays fixed. The use can change.
- 01
Long-term rental
A complete dwelling with its own access and services, subject to approvals.
- 02
Family annex
Space close by for adult children, parents or long-term guests.
- 03
Live and work
A studio or office alongside a residential loft.
- 04
Two-level home
An upper floor fit-out adds floor area, bedrooms, and living space to meet your family's needs.
- Studio / office
- Two-level home
- Lofted annex
A different order of work.
| Conventional addition | Lantern Box |
|---|---|
| Opens up the existing house early | Works outside and above first |
| Relies on the existing structure to carry the change | Gives the new work its own load path |
| Commits to the full program at once | Starts with a single storey that can expand |
| Disrupts occupied rooms sooner | Keeps the house in use longer |
| Starts from scratch every time | Adapts a tested design logic to each property |
Actual occupancy during construction depends on scope, permits and site conditions.
One property, two homes.
An illustrative scenario: a single-storey Lantern Box rented out for income.
- Existing asset
- $1.0M
- Illustrative house and land value.
- Addition budget
- $750K
- Illustrative project budget, with $650K of Phase 1 borrowed through a HELOC.
- New floor area
- +1,000 ft²
- Phase 1: a leasable one-storey loft.
- +1,000 ft²
- Phase 2: an upper floor, for 2,000 ft² in all.
- Rent recovery
- 20 years
- Gross-rent recovery target at $3,125 per month, before expenses and financing.
Once the loft is built, an owner can move from a home equity line of credit (typically up to 65% of the house's value) to a mortgage on the house plus the addition (up to 80% of the appraised value).
Illustration only, not financial advice. Lending limits, appraisals and terms depend on the lender and borrower.
Not every house should become a Lantern Box.
We screen properties against six checks, ruling out the ones that do not comply, then rank what remains and deploy the framework to the best of them. One house or a whole portfolio.
- Screen
- Rank
- Deploy
Screen
Check each property's site, structure, approvals, cost, delivery and value. Anything that does not comply is ruled out, with the reason.
Rank
Rank the properties that pass, with a one-page finding and next step for each.
Deploy
Adapt the same tested Lantern Box design to each selected site.
The same vertical addition principles apply to commercial buildings, as in our Carbon Canopy study. Lantern Box grew out of studies like Nepahwin 2.0.
Start before the project brief.
Lantern Box feasibility review
Test fit, approvals, structure, access and phasing for your house, and a clear next step.
Property feasibility scan
A one-page finding for each property, a ranked shortlist, an opportunity and constraint matrix, and next steps with a budget.