Pergolas joined like furniture.
Free-standing or house-attached. 6×6 or 8×8 milled cedar posts. Stand-off bases. Beams notched and pinned. Rafter tails proportioned to the structure. The pergola you’ll still admire in 2050.
— Why most pergolas don’t last
A pergola is structural carpentry, not landscape carpentry.
Built without joinery, pergolas rack in the wind. Built without proper post bases, they rot at the foundation. Built with the wrong stock, they check open in their first summer.
Posts buried in concrete.
Water collects between the post and the cement. Rot starts six inches below grade. Five years in, the post breaks at ground level.
Pre-cut beam saddles instead of joints.
Galvanized hardware bolt-on connectors are fast but ugly, and they introduce a different material at the connection — moisture trap, rust streak.
Big-box dimensional pine stained brown.
Sold as ‘cedar tone.’ Two seasons of UV later it’s checked, splintering, and one resin coat away from the dump.
Beam-to-post screws, no through-bolts.
Screws hold weight but not lateral load. The first decent storm racks the structure and you find the pergola half-fallen on a Sunday morning.
— Pergolas, by the numbers
— What’s included
A pergola built like a building.
Whether free-standing or house-attached, every Cairn & Cedar pergola follows the same construction standards.
Engineered footing design
Frost-line concrete piers (48″) with stainless stand-off bases. Wind load calculated for your site.
Milled Eastern white cedar posts
6×6 for standard residential; 8×8 for spans over 12 ft. From Vermont mills, kiln-dried for stability.
Mortise-and-tenon joints
Every primary connection. White-oak peg through the joint — locks tight, looks honest.
Notched, pinned beams
Beams notched into post tops, pinned with stainless rod. No bolt-through, no surface hardware.
Proportioned rafter tails
Rafter overhang and tail profile sized to the post diameter. Visual rhythm, not just structural function.
Optional climbing wire
Stainless wire grid for clematis, climbing rose, wisteria. Tensioned through hidden eye-bolts.
Optional integrated lighting
Low-voltage LED in the rafter underside. Hidden conduit, dark-sky compliant fixtures.
— How a pergola gets built
Four steps. Six to twelve weeks.
Most pergolas install in 2–3 weeks on site once material arrives. Lead time on milled cedar runs 4–8 weeks. Total project timeline: 6–12 weeks from site visit to completion.
Site visit
Two-hour walk of the property with the architect. We listen, you talk. We measure light, slope, drainage, and existing material. No PowerPoint.
Design
Hand-drawn schematic on tracing paper, then full construction drawings — material specs, sections, footing detail. Two reviews built in.
Quote
Fixed-price proposal, line-itemed by trade. Stone, timber, plants, labor, equipment, drainage. You see the math. Change orders signed before any change happens.
Build
Our in-house crew, on site every working day. Weekly progress photos. The architect walks the site at every major milestone. We don’t leave until the punch list is empty.
— Recent pergolas
Three recent cedar structures.
Lakefront master plan, 2½ acres.
Three terraced rooms stepping down to Lake Champlain. 240 ft of dry-laid stone wall, cedar pavilion, native pollinator beds.
Read project →
Seven-terrace hilltop garden.
Re-grading a north-facing slope into seven dry-stone-walled terraces of perennials, fruit trees, and a 60-foot meditation walk.
Read project →
1,400 sq ft contemporary courtyard.
Bluestone paving, cedar slat screening, a small reflecting pool, and three Japanese maples for autumn color.
Read project →10×12 to 12×16, 4-post free-standing
$14K–$32Ktypical residential
Most standard residential pergolas land $14K–$32K depending on size, height, and integration with patio. Add for climbing wire, lighting, attached canopy.
16×20+, attached to house, custom detail
$28K–$75Kcomplete build
Larger pergolas (over 200 sq ft canopy), attached-to-house designs, or pergolas with custom architectural detail (curved rafter tails, integrated screening, full lighting) run higher.
— Pergola questions
What clients want to know.
Free-standing or attached to the house?
Both work. Free-standing pergolas are easier — no flashing, no house structural review, more flexibility in placement. Attached pergolas integrate with the architecture, but require careful flashing detail and (often) a structural review of the house wall. We do both, about 60/40 in favor of free-standing.
How big should it be?
Comfortable for the use case. A pergola for a four-top dining set: 10×12. For a six-to-eight-person dining setup: 12×16. For an outdoor ‘living room’ configuration with seating: 14×18 or larger. We’ll sketch sizes during the site visit.
What about shade — does a pergola actually shade?
Open-rafter pergolas provide ~40% shade midday. For more shade, options include: tighter rafter spacing (60% shade), trained climbing plants on a wire grid (varies seasonally), retractable canvas canopy (90% shade), or fixed wood louvers. Most clients are happy with a climbing plant for season-three shade.
How do you keep it from rocking?
Joinery and footing depth. The mortise-and-tenon joints lock the structure into a rigid frame; the 48″ concrete footings prevent any post movement. We don’t use cross-bracing on standard residential pergolas — proper joinery and footings handle the load. For taller or more exposed sites, we’ll add invisible cross-bracing in the upper structure.
Can you remove an existing pergola and rebuild?
Often yes. We’ll evaluate the existing footings — if they’re at frost line and structurally sound, we may be able to reuse them. If not, we’ll rebuild from grade up. The new pergola is designed to fit the existing footprint within reason.
Do you handle electrical for lighting?
We rough in low-voltage conduit during the build. Final electrical hook-up is done by a licensed Vermont electrician we partner with — typically a half-day visit that we coordinate. Low-voltage transformer is mounted to the house exterior or in a small enclosure near the pergola.