The Point Access Block Explained.

Six stories. Twenty-four households. Four units per floor.

A point access block is a mid-rise apartment building where one centrally placed stair serves every unit on every level directly. Four to six units per floor. Up to six stories under Type I-A or Type II-A non-combustible construction, fully sprinklered, with a pressurized stair enclosure and smoke-resistant unit entry doors. The stair lands in a small shared lobby. The units open off that lobby.

Every other property of the form follows from that single move.

The floor plate

A point access block runs a 93% efficient floor plate. A double-loaded corridor runs 87%. On a 4,000 square foot plate, the six-point gap gives back 240 square feet per floor. Across six stories, that adds up to 1,440 square feet of leasable area.

Every unit has at least two exterior walls. Corner units have three. That geometry is the structural condition for cross-ventilation, because air moves between two faces when the pressure differs. Operable windows on two walls, at two heights, and the building breathes on its own.

Daylight reaches bedrooms as well as living rooms. The street side takes the living rooms. The quiet side takes the bedrooms. Each room gets the orientation it needs.

The unit mix

A point access block holds a one-bedroom, a two-bedroom, and a three-bedroom on the same plate. The plan wraps each unit from the stair core out to its own exterior wall, so unit depth is variable and unit width is variable. Bedroom counts can mix across a floor. A single resident, a couple, and a family can share the same landing.

The footprint

A point access block on a seventy-foot commercial frontage and a fifty-five-foot depth, six stories with four units per floor, produces twenty-four units on a single corner lot. A corner-store parcel holds an apartment block’s worth of households.

Cincinnati has those parcels along Hamilton, Reading, Montgomery, McMillan, and every other corridor zoned for height under the Connected Communities overlay. The form scales to each of them.

Four point access blocks along a corridor produce four distinct buildings with four distinct facades and four different owners. The street keeps its grain.

Four corners. Four buildings. Twenty-four units each. A corridor.

Graphics via Larchlab

The capital and operating ledgers

The envelope-to-floor-area ratio on a point access block is higher than on a deeper corridor building. More cladding per unit. More roof per unit. More perimeter exposed to the weather. That cost lives in the capital budget, and it is real money.

The dual-aspect, cross-ventilated, daylit unit lives in the operating ledger. At lease-up, these units clear rents at the top of the market. Tenant retention improves when residents can open two windows and see daylight in their bedrooms.

The building lives in both ledgers.

En Cojonnex Housing by RDR Architects

The energy and carbon ledgers

Cross-ventilation reduces the cooling load across Cincinnati’s fifty to seventy shoulder-season days each year. Operable windows on two faces of every unit, at two heights, move air through the unit whenever outdoor conditions support it. The mechanical cooling system sizes smaller. It runs for fewer hours each year.

Plan depth from the stair core to the exterior wall is twenty-five to thirty feet on a four-unit floor. Daylight penetrates that depth from both sides with eight-foot window head heights, so every room in the apartment sees daylight for most of the working day. Lighting loads drop across the full residential schedule. Smaller mechanical systems carry less embodied carbon. Smaller ducts. Less refrigerant.

A twelve-household building a half-block from a transit stop replaces a large volume of suburban driving across the operating life of the building. The form lands a dense household count on infrastructure that already exists.

Zurich Apartment Building by ADP Architektur Design Planung AG

Where the form can be built today

Ohio Building Code, adopted from the 2017 International Building Code, caps single-stair residential buildings at three stories. Cincinnati applies that code directly. A point access block built here today can be three floors and mathmatically maxed at eight to twelve units.

Other jurisdictions permit taller single-stair construction. Seattle has allowed single-stair residential up to six stories for several decades under Washington state provisions. British Columbia raised its limit to six stories in 2024. Virginia is among several states where legislatures have advanced similar reform.

The plan scales with the code that permits it.

The tradition

The form is old. Haussmann’s Paris. The Amsterdam canal belt. Every Barcelona block. The Berlin hofhaus. Tokyo walk-ups. Glasgow tenements. Shanghai shikumen. Every one of these traditions used a point or stacked stair core. Every one put at least two windows on every unit. Every one held mixed households on the same floor.

The form exists. The floor plates are drawn. The buildings have been standing for a century. At Trilobite, the point access block is the mid-rise floor plate we design toward whenever the parcel allows it, because it is the form that fits the parcel we actually have. The form travels.

Read more from Larch Lab’s policy brief here: https://www.larchlab.com/point-access-block-policy-brief/ and Vancouver report here: https://www.larchlab.com/city-of-vancouver-report-on-point-access-blocks/