Two reads on one house
Dollar figures are rounded or shown as proportions from the original analysis. Code provisions and engineering values are reported as documented. Square footages are rounded. The code, utility rates, tax incentives, and appraisal standards are reported as they applied during the work; some changed afterward.
Endure worked through two questions on this house. One asked what the house could become; the later work asked how to condition the house the owner chose to keep. In both cases, the owner chose another direction while retaining parts of the analysis for later decisions.
The First Read: What the House Could Become
By fall 2025 the owner of an early-1900s house in an older Fargo neighborhood was partway through a renovation that had stripped the interior and rebuilt much of the main floor. Above it sat the original half-story: low ceilings, sloped roof planes that did not meet current insulation standards, a mix of insulation types and plaster, and air sealing that could not be made continuous without opening it up. Behind the house was a later single-story addition with its own low roof. The question was what to do with all of it.
The ADU Assumption Did Not Survive the Code Check
The work began with an existing assumption: that Fargo allowed one accessory dwelling unit by right, up to 800 square feet. It is the answer a general search returns, and it had shaped early thinking about what a second-floor suite could become.
Once researched, it did not hold. The Land Development Code in Chapter 20 of the Fargo Municipal Code, as it stood in late 2025, contained no provision for accessory dwelling units, accessory apartments, secondary units, carriage houses, or any of the other usual names. The 800-square-foot figure came from general web guides that presented it as a North Dakota rule and cited no Fargo ordinance. The same read established the dimensional standards the project would actually work within: maximum building coverage of 40 percent, a 20-foot front setback, and a 15-foot rear setback for the principal structure, each different from the figures in circulation.
Three Ways Forward, and Why the Middle Ground Was Hardest to Justify
The first was to leave the half-story as it was and finish around it. It cost least. It also left the upper floor below the insulation and air-sealing target used for the reconstructed options, creating a mismatch with the rebuilt main floor below. Low ceilings would still be marked down by an appraiser, and the original framing would keep the house tied to older, smaller comparables.
The second was to bring the half-story and the low rear roof up to that target. That meant work from the exterior, a re-roof of the rear addition, and continuous air sealing through assemblies never built for it. The house would perform, but over its new floor the upper story would keep its original walls and roof, with low, sloped ceilings.
A more complete version of the second option would tear off the existing half-story walls and roof and rebuild the main house with a full-height second story under a simple gable roof. That simplified air sealing and insulation and removed the low, sloped ceiling geometry. By the time the work reached that scale, some of the reconstruction required for a full second story was already being bought.
The third extended that full second story over the rear addition as a private suite with an internal connection to the house, its own exterior entrance, and a wet bar. Without the suite, the rear addition could stay as it was, or be re-roofed to bring its roof assembly to the reconstruction target. Extending the second story over it as the suite was the marginal step, about $50,000 in the analysis, and added little HVAC cost because much of the mechanical work was already required for the rest of the house.
The work’s view was that the ground between leaving the half-story alone and rebuilding it fully was hardest to justify: once the owner was paying to reconstruct the upper story, extending it over the rear addition bought a fourth bedroom, income potential, and a different appraisal for a comparatively smaller increment.
Cladding Decided by Elevation
The planned reconstruction set the exterior material one elevation at a time, against the direction each facade faced, durability at the snow line, cost over forty years, and how an appraiser would read it.
The street-facing elevation was to use brick or lime plaster because it carried the strongest appraisal read. Wood was planned on the other elevations, with a continuous brick base around the snow line. In the analysis, wood lap siding with a linseed-oil finish over a rainscreen had the lowest estimated forty-year cost. That holds only if the periodic recoating is owner labor; with contractor labor, the advantage narrows or disappears.
This was planned for the reconstruction option and was not built.
What the Money Had to Do
The renovation was already caught between expected project cost and expected value. The read quantified that gap and tested what each option did to it.
Under the first option, the gap remained under the appreciation assumptions used in the analysis.
Under the third, the logic changed. With the entire wood-framed portion of the house new, and only the basement and crawlspace original, the work targeted a C2 condition rating, the category used for older properties that have been recently completely renovated, with an effective age of zero to three years. Effective age is an appraisal judgment rather than a prescribed value, and it shapes which houses are credible comparables: newer houses in outer neighborhoods, where values per square foot run higher, rather than the older houses nearby.
The work also targeted Q3 quality and reasoned backward from it. In the analysis’s judgment, replacing hardwood with vinyl plank or hard-surface counters with laminate risked pushing the quality read toward Q4, while cabinet tier, quartz against granite, tile quantity, and trim complexity could move without costing the target. Finish decisions were therefore tied to the appraisal classification rather than treated as a generic upgrade budget.
The analysis projected that the suite would add roughly twice its incremental cost in value, and that the completed house could appraise for about what the project had cost, with income potential from the suite on top. The added value would arrive after construction and appraisal, while the added construction cost would arrive first.
The Residential Green and Energy Efficient Addendum was planned as a formal record of the house’s measured energy and building-performance information for the appraisal. A blower-door result was to anchor it. Sent with the appraisal order and left at the house for inspection, the addendum would put that information in front of the appraiser alongside the condition, quality, and effective-age analysis.
The work also asked whether the location itself was sound, and priced ownership the way it is actually paid: mortgage, taxes, insurance, and special assessments together. Reporting in 2025 documented special assessments of tens of thousands of dollars per home in newer subdivisions elsewhere in the Fargo metro, including cases where the assessment increased the owner’s monthly payment after purchase. Fargo itself typically amortizes special assessments over fifteen to twenty-five years with interest. Against the typical annual installment used in the analysis, the subject property’s legacy assessments were roughly one-eighth as large. Priced that way, the established neighborhood carried the smaller recurring obligation. Fannie Mae’s Selling Guide separately treats special assessments as relevant to property value and marketability.
The Incentives, Mapped Apart From the Base Economics
The work also mapped federal credits, North Dakota’s remodeling exemption, utility rebates, and local programs. Eligibility depended on ownership, timing, and how the construction scope was classified, so the incentive map stayed separate from the base economics of the project.
How the Work Was Planned
The construction estimate did not rely on unit pricing alone. The carpenter who had already reframed much of the main floor had billed hourly, itemized by scope, and those records were aggregated into productivity rates: how long this crew actually took to frame a wall or set a window in this house. That gave the remaining carpentry work an estimate grounded in the building itself, and a way to sanity-check any hard bid that came in.
Those productivity rates carried into the schedule, where the order of work was set by the physical sequence required to keep the house protected during reconstruction. The sequence was first worked out for a fall 2025 construction push and developed further as the project changed. It went through five analytical iterations using verified productivity from earlier work and repeated field review. Multiple gable orientations were modeled against sequencing, cost, how the roof intersections would land, and which arrangement left the most room for error in measurements that could not be taken until the work was further along. The final arrangement allowed the trusses to be ordered in one lot, with a small opening used to establish the house dimension and a second point verified later. At the north roof, roughly four-foot sections would open one at a time. Most bearing shims were to be pre-set by laser before demolition. A floor truss would be flown into each opening, with subfloor following behind the truss crew while the half-story was demolished in parallel. The southwest porch would be rebuilt as conditioned space while the north roof-to-floor transition continued. Walls and roof would close each section before the next opened, keeping the main floor covered as the work advanced. The house’s shape let the separate operations proceed without crossing the telehandler path. Where the boom could not reach, trusses could be set on finished subfloor and slid into place. The scope was never built. The sequence is described here as planned.
The Recommendation, and What Followed
Endure’s recommendation was the third option: build the full second story and the suite. The same work set out the added construction burden: six to nine more weeks of work and more trades to coordinate.
The owner kept the half-story as it was. The financial work and the expected Fargo Land Development Code change left the owner with information that could be reused for future work on the lot, including the rental and value analysis.
The Second Read: The House as Kept
In summer 2026 the question narrowed: how to condition the house as it would now be finished.
The existing gas furnace still worked and could stay in the basement for the storage and mechanical spaces, but it had no air conditioning and made distribution to the main floor and half-story complicated. The main floor and half-story needed their own system.
The Building as Measured
The second read began with a measured survey of the building as it stood: about 1,200 square feet conditioned above grade, roughly two-thirds of it on the main floor. The half-story keeps its original framing and windows, with mineral wool in all accessible cavities. The rear addition stays single-story, with insulation at its roofline and its low attic inside the insulated envelope, where the air handler would sit. The basement stays on its existing gas furnace, held at 60 F. The floor between the basement and the main floor is left uninsulated on purpose: the basement has its own furnace, heat rising through that floor stays in the house, and the package counts it as a known load rather than paying to stop it.
The survey was built room by room and checked against the building as a whole. Each room carried its dimensions, volume, wall and ceiling areas, wall exposures, window orientation, overhangs, assembly details, and available NFRC thermal data. The gross envelope was measured separately so partitions, framing, conditioned attic space, and the floor assembly remained accounted for outside finished-room dimensions. Any unreconciled difference stayed visible.
Moving the Air Handler Simplified the System
The research found no ducted gas furnace that would fit and work in an attic with about two feet at the ridge. Compact heat pump air handlers built for tight spaces could, and putting one in the conditioned attic gave the main floor and half-story a much more direct distribution path while the existing furnace stayed in the basement. The new system would provide both heat and air conditioning. The package also planned a balanced ERV in place of relying on bath fans for ventilation because of the tighter main-floor envelope, and mapped exhaust locations and exterior clearances around the dryer, outdoor HVAC equipment, and exterior electrical equipment.
A small-duct high-velocity system was considered, but the limited amount of ductwork meant it solved little while adding complexity and reducing access to local installer knowledge.
The Handoff
The package was written for the mechanical contractor or mechanical designer who would run the certified calculation in licensed software and select equipment. It is explicit about which parts of the work are theirs.
Its first page states what it is not: not a certified Manual J, S, or D calculation, and not to be built from until the selecting mechanical contractor or licensed designer runs the required calculation in approved software. It then sorts its contents. The measured survey is presented as closed. The inputs come with their basis: heating design temperature set colder than the ASHRAE 99 percent value for Fargo, close to the more conservative 99.6 percent value, buffer-space temperatures reasoned room by room, assembly values researched. The two items that genuinely had to be assigned, infiltration and the cooling method, are identified as the place where a different answer would come from. Equipment findings are labeled by source, so that calculated figures, manufacturer literature, and design direction are never mixed.
The preferred sequence was to complete the envelope, blower-door test it before final equipment selection, then verify the finished system during commissioning and air balancing. No blower-door result was available when the equipment decisions were being made, so with a leaky original half-story above a substantially rebuilt main floor, the preliminary load carried the leaky end of its infiltration range. Air leakage is 36 percent of that preliminary heating load. The leakage range changed the margin within the selected equipment step without moving the load into another equipment size.
A blower-door result was planned as the addendum’s anchor number in the first read, and the same test was recommended again in the second.
It turns a concern into a criterion. The owner’s question was simple: if the heat pump quits at 30 below, will the house be all right? The package answered it as a design criterion: electric auxiliary heat sized to carry the full design load alone, with the compressor assumed unavailable. It labels that as a conservative project choice and keeps it separate from general sizing rules. The auxiliary-heat check also showed why nominal equipment ratings were insufficient. Resistance-heat output changes with delivered voltage, so the package made voltage under load a field condition to verify before treating the heater’s nameplate output as available capacity.
One candidate indoor unit was checked against its installation manual, which sets a minimum installation ceiling height the attic could not provide. The finding applies to that unit only; other models from the same maker were not checked.
It leaves unresolved items with the people who can resolve them. For the leading candidate, the indoor unit named in the certified performance data does not match the designation in current product literature, two certification numbers appear in the record, and the modeled airflow meets the manufacturer’s per-ton limit only once the filter is loaded. The package lists these as questions for the manufacturer and the selecting contractor, and notes that if the manufacturer cannot answer them, that is itself a reason to look elsewhere.
The package sequences the carpentry that conceals the duct after the duct is hung, and flags an item outside mechanical scope, a crawlspace ground cover, that sits on the critical path. No duct-design software was used, and the package says so; the routing is offered as coordination for the designer to confirm.
A contractor entry sheet carried the survey, assemblies, design conditions, preliminary loads, airflow schedule, and duct segments as flat values for entry into load software. It contained no formulas or live links. The calculation model remained separate and was available to a licensed mechanical designer engaged under a design contract. Responsibility for independent calculation, equipment selection, code compliance, and final design stays with the selecting contractor or licensed designer.
What the Package Was Used For
The owner did not pursue the equipment direction the package set out. The loads were used instead as a check: on the existing equipment, and on what contractors proposed. Most of the proposals the owner received differed widely from the package’s loads without showing the data or calculations behind those differences. All but one contractor neither asked for the windows’ rated performance nor looked at it on their site visits, and no proposal showed how window orientation or load had been accounted for. The main-floor windows are triple-glazed and rated at roughly half the solar heat gain assigned to the unrated half-story windows, which were modeled at a typical new-construction value. A load built on assumed window values misses that. The package gave the owner a way to tell which bidders had done the work.
What the Two Reads Show
The first read found that a question about a second floor was a question about capital, laid out three options against what the house could appraise for, and made a recommendation. The second measured the house the owner chose, separated what was known from what was assigned, and drew the line to the mechanical trade with the building information already assembled and the remaining decisions left visible. The owner did not adopt the first read’s recommendation or pursue the equipment direction developed in the second. Both pieces of work were used to make the decisions that followed. Each question began smaller than the system that ultimately set the answer.