Window Field Guide · Triple-Deckers & Stacked Flats

Triple-decker windows: measure every floor separately

Three-family wood-frame buildings from the 1890s–1920s repeat a floorplan — but almost never repeat the same opening size after a century of settlement. Boston landlords reorder 1" vinyl mini more than any other line for turns. This guide covers mount methods by material, not a tourism page about the city.

Common in: Boston · Cambridge · Somerville · Quincy

Quick answer

What owners standardize on across Allston, Dorchester, Somerville, and similar stock:

  • 1" vinyl mini — default for every floor's bedrooms and kitchens
  • Measure each window; third-floor openings often differ from the first
  • Outside mount common when plaster returns are shallow or out of square
  • September turnover season — order early for August make-ready
  • Shipped from Texas — hire a local installer for ladder-heavy floors
  • Ships nationwide from Texas
  • Custom cut to measured size
  • Mini, vertical & faux wood lines
  • Mount notes by material

Triple-decker window reality

Each floor is its own unit, but the building shares construction DNA: double-hung windows, wood trim, shallow returns, and seasonal expansion that throws off square openings.

  • Front bay windows may be wider on the first floor than upper floors — do not copy measurements floor to floor
  • Kitchen and rear stair windows are often smaller — vinyl mini in the 22"–28" width band
  • Side-by-side doubles sometimes need one outside mount and one inside mount in the same room
  • Lead paint and old plaster mean gentle drilling — cracked returns need repair before brackets load
  • Heat season can bind inside-mount products — leave factory clearance, do not over-tighten

What Boston-area turns actually look like

Mini blinds dominate reorder volume. Below: our vinyl line (collage), vertical for sliders, and faux wood when depth allows.

1" vinyl mini blinds — Boston turnover favorite

Landlords and owner-occupants reorder white cordless vinyl mini across all three floors. Custom width and length — ship to Massachusetts.

Configure vinyl mini
1 inch cordless vinyl mini blinds on a bedroom window
Close-up of vinyl mini blind slats and headrail
Vinyl mini blinds installed in an apartment unit
White vinyl mini blinds — standard turnover color
Cordless vinyl mini blinds on a dark trim opening

3.5" vertical blinds

For rear sliders and rare first-floor deck doors — 68×84 and 78×84 stock patterns.

Shop vertical blinds
Vertical blinds on a sliding door
Vertical blind vanes and track

2" faux wood blinds

Front-room upgrade when trim depth supports it.

Shop faux wood
Cordless 2 inch faux wood blind — white

Typical opening → blind size

Typical reorder bands for shipped Boston-area turnover orders:

Opening (approx.)Order sizeRoom
22"–28"21.5"–27.5"Kitchen / rear stair
30"–36"29.5"–35.5"Bedroom
46"–48"45.5"–47.5"Wide front room
68" × 84" slider68" × 84" verticalRear deck slider (when present)

Mounting by material & situation

Boston triple-deckers reward the same discipline as NYC pre-war stock: pick mount type from depth and substrate, then pick material.

1" vinyl mini blinds

View product line →

Highest-volume product for Boston turns — light headrail, cordless, easy to replace window-for-window on the next vacancy.

  • Inside mount — square wood jamb

    Use narrowest width and longest height. Factory deducts width for clearance. Best on newer sash replacements with flat jambs.

    Min depth:
    ≈ 1" clear
    Hardware:
    Supplied brackets; #8 wood screws typical

  • Outside mount — settled plaster returns

    Pro often used

    The usual choice when the opening is out of square or depth is under 1". Mount to the flat trim face; overlap 1½"–2" per side.

  • Upper-floor long drops

    Pro often used

    Third-floor bedrooms often need 72"–84" drops. Confirm ladder access for install — many owners hire out upper floors even when they DIY the first.

2" faux wood blinds

View product line →

Used on front rooms when owners want a step up from mini — verify depth first.

  • Inside mount

    Pro often used

    Needs deeper return than vinyl. Measure depth at both top corners — settlement often leaves one side shallower.

    Min depth:
    ≈ 1½"–2½"

  • Outside mount on wide bay trim

    Pro often used

    Front bay windows sometimes need one wider outside-mount unit. Measure the full trim width you want covered, not individual sash widths.

3.5" vertical blinds

View product line →

Less common than mini on classic triple-deckers but used on rear sliders when present.

  • Wall-mount track above slider

    Pro often used

    Face-mount track when ceiling is uneven near the porch header. Keep stack side clear of the door handle.

Pro install vs DIY on triple-deckers

First-floor turns are often DIY or handyman work. Third-floor long drops, outside mount on cracked plaster, and bay windows push most owners toward a local installer — especially during August make-ready before September leases. We ship sized product from Texas; professional installation is offered in DFW only. For Boston properties, order by SKU and send our mount notes to whoever is on site.

Frequently asked questions

Why do Boston landlords order so many vinyl mini blinds?

Cost per opening, fast replacement on turns, and fit on shallow triple-decker jambs. One white spec across units simplifies reorder — match part number to opening size.

Should I use the same sizes on all three floors?

Same product line, not necessarily same width. Measure every opening. Bay fronts, rear kitchens, and upper-floor replacements often differ.

Do you deliver to Boston?

We ship custom-cut blinds nationwide from Texas. Transit time depends on carrier service to your ZIP — not same-day like our DFW apartment turnover stock.

Inside or outside mount for settled plaster?

When depth is under 1" or the opening is visibly out of square, outside mount on the trim is safer. Repair crumbling returns before loading brackets.

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