The Envelope Works · Thermal-envelope studio · Pember Hollow · By appointment

Your house wears a coat. We tailor it.

The Envelope Works treats the building as one garment — walls, attic, basement sill and the ventilation that has to come with a tight weave. Infrared surveys, dense-pack installation, balanced HRVs, and a blower-door number chalked on the workroom wall for every house we have closed since the studio opened.

Nine years of instruments

The studio, in readings

A tailor measures twice; we measure with a fan, a camera and a moisture meter, and the workroom wall keeps the chalk tally. The figures are the studio’s fitting room — every number below was a house, and every house got its number.

612
envelopes closed since the studio opened
−47%
median CFM50 reduction on last season’s chalk
R-60
over every flat we finish — sealed first, always
9 yr
of binders, plates and chalk marks on the wall

What we do

What the studio fits

Walls, dense-packed to the gauge

Walls, dense-packed to the gauge

Cellulose blown to three and a quarter pounds per cubic foot — gauged, not guessed — inside bays photographed empty and photographed full. R-13 to R-15 added where there was siding and hope, and the thermal-gradient plates in your commission file showing the stripes gone.

Attics & the roofline

The flat air-sealed and dressed to R-60; cathedral bays dense-packed to R-38 with the ventilation channels kept clear and photographed. Skylights, flues and fixtures dressed to real clearances — the tailor’s part, where the difference between a coat and a blanket lives.

Attics & the roofline
Ventilation, balanced & measured

Ventilation, balanced & measured

An envelope that holds air needs lungs that work: HRVs commissioned with an airflow report, moisture strategy drawn per house, and the humidity dial landing where the physics said. The studio does not sell tightness without selling breath.

Commissions & rates

The studio card

Prices from last season’s commissions, each one ending in a number the door or the gauge can check. The fitting — the infrared survey with both blower-door readings — is free with any commission and $240 on its own, waived against work within the year.

The fitting — survey & test-in$240, waived

Fan, camera, moisture notes, the plates — free with any commission below

Air sealing commissionfrom $1,520

The holes the plates named, sealed — the running count in the file

Walls, dense-packedfrom $3.35 / sq ft

Per sq ft, density gauged and printed

Attic & roofline to R-60from $2.65 / sq ft

Per sq ft over the flat, bays to R-38, clearances dressed

HRV commissionedfrom $4,250

Balanced, airflow report, humidity strategy drawn

The closing readingincluded

Test-out against the named target — chalk on the wall

How it goes

A commission, fitted to closed

The same sequence on every job — the only variable is your project.

  1. Week 1

    The fitting

    The fan, the camera, the moisture meter, and two hours of looking properly. Out comes the commission file: plates, readings, and a scope cut to the house rather than to a package — because a coat is fitted, not sized off a rack.

  2. Week 2

    The under-layer

    Air sealing — the garment’s lining. Top plates, penetrations, the rim joist at the sill, the hatch; the smoke pencil and the running CFM count, every fix noted in the file as it lands.

  3. Weeks 3–4

    The cloth

    Dense-pack to the gauge in the walls, R-60 over the flat, bays packed with channels preserved. The bays are photographed empty and full — the studio’s habit and the file’s best pages.

  4. Week 5

    The closing reading

    Test-out against the target the commission named, HRV balanced if the scope carries one, and the new number chalked on the workroom wall beside six hundred and twelve others.

2025 — 2026, Pember Hollow & the Cartway

The commissions file

Six pages from last season’s files. The full commissions — plates, densities, both readings — are bound per house and a copy goes home with every customer, because a coat you cannot inspect is a coat you cannot trust.

The Hollow semi
The Hollow semi — R-60 flat, skylights dressed, hatch sealed
Cartway storefront dwelling
Cartway storefront dwelling — bays packed, stripes gone from the plates
The empty-bay plate
The empty-bay plate — photographed before the hose, as always
The gauge at 3.25 lb/ft³
The gauge at 3.25 lb/ft³ — the density the card promises
Closing reading day
Closing reading day — the fan back in the door, the chalk waiting
The balanced lung
The balanced lung — HRV commissioned, report in the file
They talked about the coat for ten minutes and then measured the house for an hour — the fan, the camera, a moisture meter along the sills like a doctor with a stethoscope. The commission file arrived cut to our house: seal here, pack there, ventilate because the numbers said so. February came and the coat fits.
A. & P. Sillitoe · Full envelope — Hollow semi
The bays were photographed empty and full, the density was printed, and the closing reading went on their wall in chalk while I watched — 1,310 down to 640, same fan. I have hired a lot of trades and this is the first one whose invoice I could check line by line against photographs.
Marguerite Vance · Walls + attic, the Cartway
Our 1908 house had "breathe" quoted at us three times as a reason not to seal it. The studio drew the ventilation line first — HRV sized off the test-out target — and closed the envelope second. The windows stopped weeping, the hallway stopped howling, and the hygrometer sits at 42 all winter. The lung came with the coat.
The Ferreira-Nunes · Envelope + HRV, Pember Hollow

Fair questions

The fitting-room five

The five every consultation reaches by the second fitting. The studio line answers between eight and six, Hollow time, and the workroom wall answers louder.

Why a studio and not a contractor?

Because a contractor sells a package and a studio cuts to measure. The instruments decide the scope — the fan says how leaky, the camera says where, the moisture meter says what the walls can take — and the commission is priced off those readings. It is the difference between buying a coat off a rack and having one fitted, and the difference shows up on the first February bill.

What R-values will my house actually achieve?

Per assembly, in the commission file before you sign: walls typically R-13 to R-15 added, cathedral bays R-38 within the ventilation, the flat attic R-60. The word "achieve" is doing real work there — the closing reading and the printed densities are how you know the number on the invoice became a number in the house.

Is dense-pack messy in an old house?

It is surgical, which is the honest answer: two holes per bay, fill to the gauge, plug and patch the same day, furniture sheeted and the hose living in one window. The empty-and-full photographs are partly quality control and partly proof that nothing was filled that should not have been.

Do I need an HRV if my house is old?

If the closing reading lands tight of healthy — which happens more in old houses than the folklore expects, once the big holes are sealed — then yes, engineered ventilation beats accidental draughts in every measurable way: dry air, controlled humidity, heat recovered instead of lost. The studio computes the line before the scope, so it is never a surprise after one.

What does the chalk wall actually prove?

Six hundred and twelve houses’ worth of accountability: a number per house, in order, in public, inside the shop. Customers walk in, find their line, and point at it — which is the whole relationship the studio exists to have with the work. The wall has never once been repainted.

612
chalk lines on the workroom wall, one per envelope
−47%
median CFM50 reduction across last season
−29%
median first-winter heating change, same thermostats
100%
of commissions closed with a printed test-out reading

Fittings booking two weeks out across the Hollow & the Cartway · (555) 028-7745 · studio@envelopeworks.example

Book the fitting

We come with the fan, the camera and the moisture meter, and leave the plates and both readings in a file with your name on it. The commission that follows is cut to the house the instruments describe — never to a package. Evenings suit the Hollow; Saturdays suit the Cartway. studio@envelopeworks.example

The fitting request