MDU fiber engineering services for apartments, condos, mixed-use buildings, and senior living communities. Riser design, splitter placement, floor plan overlays, and construction-ready packages — active in 22 states, available across all 50 U.S. states.
MDU fiber engineering services cover a design discipline that standard outside plant engineers don't always know well — and the gaps show up in the field. Most FTTH design services stop at the building entrance. MDU engineering is everything from that demarcation point inward: riser conduit pathways, IDF and MDF placement, splitter locations inside the building, floor-by-floor distribution routes, and individual unit drops to the ONT. That's inside plant work — a different set of standards, different cable types, and a completely different relationship with the property owner.
The OSP/ISP boundary in an MDU project isn't just a technical line — it's a contractual and regulatory boundary too. Outside that wall, you're dealing with municipal ROW permits, utility coordination, and aerial or underground construction norms. Inside, you're dealing with the building owner's approval, NEC compliance for conduit fill, plenum or riser-rated cable selection, and floor penetration fire-stop requirements. We've seen projects stall for six weeks because the design team didn't account for the building owner's riser access policy. That's not an OSP problem. It's an MDU problem.
Vertical distribution is the core technical challenge. In a 12-story building with 8 units per floor, you need a riser system that gets fiber from the building MDF up through every floor's IDF without creating conduit fill violations, without chewing through plenum-rated cable budget, and without designing yourself into a dead end when the tenant on the 9th floor eventually wants a 10 Gbps upgrade. The design decisions made in the riser — centralized vs. distributed splitter placement, homerun vs. daisy-chain topology, 1:4 vs. 1:8 vs. 1:16 split ratios — can't easily be undone after construction. Get them right the first time.
Active in 22 states. First 20,000 LF project free — no commitment. We've done MDU fiber engineering across apartment complexes, senior living campuses, mixed-use high-rises, and student housing. If your project has a building or a riser, we can design it. Start with a free design.
Our MDU fiber engineering process runs from initial site walk through to a construction-ready package that contractors can build from without interpretation. Here's the sequence we follow on every MDU project, whether it's a 30-unit garden-style apartment or a 400-unit high-rise campus.
We start in the building. A riser survey captures the existing conduit system — locations, fill, sleeve sizes, penetration openings — along with MDF/IDF room dimensions and access points, existing network equipment, and any building-owner constraints on routing. For retrofit projects, you can't skip this step. For new construction, we coordinate with the GC to get the rough-in scope right before walls close. Assumptions made at the desk without a site walk create RFIs. We don't design MDU projects without one.
Splitter location determines signal levels at every ONT in the building. We model the optical link budget from the OLT port through the feeder fiber, the splitter, and the distribution fiber to each ONT — working backward from the 1 dB margin that keeps you out of trouble during a splice re-do or a connector cleaning. For a 1:8 centralized splitter in a 200-unit building, that calculation has to account for 6.2 dB of splitter insertion loss plus 0.35 dB per km of cable plus connector losses. We don't estimate — we calculate. See our guide on FTTH LLD splice point placement for the methodology we apply to distribution design.
Homerun topology runs individual fibers from the central MDF to each floor IDF or each unit. More fiber, cleaner troubleshooting, easier future upgrades. Daisy-chain topology passes a single cable through multiple IDFs, tapping at each floor. Less cable, more complex splicing, more failure points. Most MDU designs we deliver use homerun for the vertical riser segment and a short daisy-chain only within a single floor where unit count doesn't justify individual drops. The right choice depends on unit count, floor layout, and the carrier's long-term upgrade plans.
Conduit fill calculations per NEC Chapter 9 (Table 1) govern how many fibers can share a conduit without exceeding the 40% fill ratio. We produce a conduit schedule for every riser segment and every floor lateral run, including the appropriate conduit diameter for the fiber count and cable type. ONT placement for each unit is documented with a location, power source, and wall-mounting detail. The fiber distribution hub sizing guidance we follow on OSP projects applies to MDU IDF cabinet sizing as well — the principles translate directly.
The final deliverable is a complete fiber construction package — riser diagrams, floor plan overlays, splitter placement drawings, conduit fill calculations, cable schedules, and as-built documentation requirements. It's delivered in PDF and CAD formats. Contractors get what they need to build without calling us for clarification. That's the standard we hold every package to.
MDU fiber networks can be built on Active Ethernet or GPON architectures — and the right choice isn't obvious until you've run the unit economics. Most MDU deployments over 50 units go GPON because the passive optical architecture eliminates active equipment in every IDF, which reduces power requirements, heat load, and maintenance overhead inside the building. A detailed GPON network design guide covers the architecture decisions that apply here.
Active Ethernet is worth considering for buildings where the property owner is supplying the LAN infrastructure and the ISP is only responsible for the building entrance connection, or for luxury properties targeting sub-10ms latency guarantees on symmetric 10G service. It's also simpler to troubleshoot at the unit level — a dead port is a dead port. GPON troubleshooting requires optical power meter readings and an understanding of the split ratio's effect on Rx levels.
A switch in every IDF, dedicated fiber per unit, full symmetric bandwidth. Best for high-end properties with 50 units or fewer, or builds where the property supplies the LAN. Higher equipment cost, lower OpEx after install. Simpler per-unit troubleshooting.
Passive splitter tree, shared wavelength per PON port, 1:4 to 1:32 split options. Best for 50+ unit MDUs. No active equipment in risers. Lower equipment cost, manageable OpEx. XGS-PON (10G symmetric) is the current standard for new builds.
Single splitter in the building MDF serves all units. More cable runs to each floor, but one splice location, easy access for maintenance, lower per-split cost. Best for buildings under 150 units where riser fiber runs don't get prohibitively expensive.
Splitters at each floor IDF. Shorter distribution runs per unit, lower cable volume from the MDF. More splice points, more potential failure locations. Best for large buildings over 150 units or any building where floor IDF rooms exist.
Split ratio is one of the highest-stakes design decisions in MDU fiber engineering — and it's permanent once you've commissioned the splitter plant. Don't guess.
The splitter topology question comes up on nearly every MDU project we touch. There's no universal right answer — the right choice depends on unit count, building layout, and how much the property owner values future flexibility vs. upfront construction cost. Here's how the two architectures compare across the factors that actually matter in the field.
| Factor | Centralized Splitter | Distributed Splitter |
|---|---|---|
| Installation Cost | Lower splitter hardware cost; higher riser cable volume to reach each floor | Higher hardware cost at each floor IDF; lower cable volume from MDF to floors |
| Troubleshooting | Single access point for all splitters — faster to diagnose and clear a fault | Multiple IDF locations require floor-by-floor access, slower isolation |
| Future Upgrades | Easier to replace or re-split from one location; less disruption to tenants | Each floor IDF requires a separate upgrade visit; more tenant coordination |
| Cable Volume | High — feeder fibers run to every floor or unit cluster from central MDF | Low from MDF to each floor; short distribution runs within each floor |
| ONT Distance Limit | GPON max 20 km; practical MDU distance well within limit even for tall buildings | Shorter distribution runs give better signal margin at high split ratios |
| Best For | Buildings under 150 units, buildings with limited IDF rooms, retrofit projects | Buildings over 150 units, new construction with dedicated IDF rooms per floor |
Every MDU fiber engineering engagement from Draftech delivers a construction package — not a preliminary design, not a conceptual drawing. Contractors shouldn't need to call us after delivery to ask what something means. Here's what's in every package.
The deliverables we produce are specifically designed for contractor use. Every cable run is labeled. Every splice point is called out. Pull sequences are documented for riser segments where the conduit fill makes order of installation matter. We've seen too many MDU projects where the design looked clean on paper but the contractor couldn't figure out the installation sequence — that's a design failure, not a construction failure.
MDU buildings frequently appear as underserved or unserved locations in BEAD fabric challenge and eligible area maps — particularly older apartment stock in urban cores and rural multi-family housing that's never had anything faster than DSL. NTIA's rules count each unit as a serviceable location, which means a 200-unit apartment building counts as 200 locations for purposes of grant coverage calculations. That changes the economics of MDU engineering significantly for BEAD subgrantees.
We understand the BEAD engineering requirements for subgrantee projects and design MDU packages that meet them. That means unit-level coverage documentation — not just a service address at the building — and as-built deliverables that match state broadband office reporting standards. Some state programs have specific requirements for how MDU units are documented in the network inventory. We've navigated those requirements in more than a dozen states already.
Grant compliance documentation for MDU projects typically includes: a unit address list with fiber path documentation for each unit, signal level records at ONT commissioning, riser diagrams as submitted and as-built, and any property owner access agreements required by the granting authority. We document to that standard on every BEAD MDU project — not because auditors will eventually ask, but because sloppy closeout documentation is one of the most common reasons BEAD subgrantees face clawback risk at final reporting. Our OSP engineering services include the outside plant portion of the same build, so we can cover the full project from feeder to unit in a single engagement.
MDU + OSP in one scope: Most MDU fiber projects include an outside plant component — the feeder from the serving hub or CO to the building entrance. We design both in the same engagement, which eliminates the handoff gap between OSP and ISP design that causes conflicts in the field. One team, one construction package, one point of contact for RFIs.
FREE FIRST PROJECT
Active in 22 states. First 20,000 LF project free — no commitment. MDU engineering included for projects with an OSP component.
MDU fiber engineering is the design and documentation work required to bring fiber optic service to individual units inside a multi-dwelling unit building — apartments, condos, mixed-use developments, student housing, and senior living facilities. It covers everything from the building entrance point through the riser system to the ONT at each unit. Unlike standard OSP FTTH design, MDU fiber engineering deals with inside plant infrastructure: riser conduit pathways, IDF/MDF placement, splitter locations, floor plan overlays, and conduit fill calculations. The result is a construction package that contractors can build from without guessing. Learn about our FTTH design services for the outside plant portion of your project.
Standard FTTH design is primarily outside plant — aerial or underground runs from a central office or headend to the side of a building or a demarcation point. MDU FTTH engineering picks up where OSP ends. Inside the building, you're dealing with riser conduit systems, mechanical rooms, IDF/MDF closets, floor-by-floor distribution, and individual unit drops. The cable types change (plenum or riser-rated rather than outdoor OSP cable), the splice points are inside rather than in vaults or closures, and the relationship with the property owner adds a layer of access and approval coordination you don't have on standard FTTH. The design disciplines are related but not the same.
Split ratio selection for MDU fiber depends on unit count, building density, and the service tiers you plan to offer. A 1:4 split delivers maximum bandwidth per subscriber and works well in luxury or high-density buildings where symmetric gigabit is the product. A 1:8 ratio is the most common choice for mid-density MDU — it balances cost and performance for 100 Mbps to 1 Gbps tiers. A 1:16 split is used in large complexes where cost efficiency matters and you don't anticipate heavy simultaneous usage. For BEAD-funded MDU projects, check the subgrantee's required service standards before selecting a ratio — some grant programs specify minimum speed thresholds that influence your architecture choices.
A typical MDU fiber engineering engagement runs 3–6 weeks from site walk to completed construction package, depending on building complexity and unit count. A single 50-unit mid-rise with a straightforward riser system might take 2–3 weeks. A 400-unit campus with multiple buildings, phased construction, and mixed new-build and retrofit sections can run 8–12 weeks. The biggest variable isn't design time — it's the site walk and as-built documentation availability. Buildings where the existing riser infrastructure is well-documented are faster. Buildings where you're working from a 1987 floor plan that doesn't match current construction add real time to the schedule.
Yes. MDUs are frequently identified as underserved or unserved locations in BEAD eligible area maps, and subgrantees must document coverage to individual units — not just building addresses. We provide full grant-compliant MDU engineering packages including riser diagrams, floor plan overlays, unit-level coverage documentation, and as-built closeout deliverables that meet NTIA and state broadband office requirements. We've worked with BEAD subgrantees across more than a dozen states on MDU design scopes and understand the documentation standards required for milestone and close-out reporting. See our overview of BEAD engineering requirements for context on what subgrantees need from their engineering partners.
Standard MDU fiber engineering deliverables from Draftech include: riser diagrams showing conduit pathway from building entrance to each floor, floor plan overlays with fiber routes and ONT placements marked, splitter placement drawings with signal level calculations, conduit fill calculations per NEC, a complete construction package in PDF and CAD format, and as-built documentation requirements. For BEAD projects, we add grant compliance documentation and unit-level coverage records. All deliverables are construction-ready — no interpretation required on the contractor side. Our fiber construction package deliverables guide details exactly what a complete package should contain.
Yes — and they're genuinely different scopes. New construction MDU design is coordinated with the general contractor during the rough-in phase. Conduit sleeves, pull strings, and MDF/IDF rough-in boxes get designed into the building before walls close. Retrofit design works around what's already there — routing through existing conduit, cable trays, or exposed raceway. Sometimes the original conduit was never sized for fiber. Retrofit projects take more site-walk time and produce more creative routing solutions, but both result in the same complete construction package. We've done both in the same multi-building campus where one tower was under construction and the adjacent tower was a 1970s retrofit.
MDU fiber engineering is scoped per project based on unit count, building type, and design complexity. A straightforward single-building MDU design typically runs $2,800–$6,500 depending on size. Multi-building campus projects and retrofits with complex existing infrastructure are priced individually — we'd need a scope conversation before quoting. The first 20,000 LF of design for new clients is free with no commitment, which often covers the OSP portion of a combined MDU plus aerial or underground build. Contact us to scope your project — we respond within one business day.
ARE YOU AN MDU FIBER ENGINEERING FIRM?
This page describes the service we deliver to clients. If you provide MDU fiber engineering and inside plant design and are looking for a consistent subcontract pipeline, we have ongoing capacity needs in this discipline.
Tell us the building type, unit count, and whether it's new construction or a retrofit. We'll scope the MDU engineering and let you know if the OSP component qualifies for our free first-project offer. We've done this in 22 states — if there's a building or a riser involved, we know how to design it.
Get Free DesignCall us directly: 305-306-7407 — or email info@draftech.com. We reply within one business day.
SERVICE AREAS
Active in 22 states and deployable across all 50 U.S. states — including our highest-volume BEAD markets:
View all service areas →Draftech International provides MDU fiber engineering services across all 50 U.S. states — from small regional ISPs and electric cooperatives to Tier-1 carriers and BEAD-funded subgrantees. Contact our engineering team to discuss your project.