Live Design Revisions

Quick Anwers

Why does the solar design always change after the site visit?

Because the number that matters most is a forecast about the customer's future, and no satellite image contains it.

A rep arrives at a house in Ghaziabad with a 5 kW layout drawn from aerial imagery. Twenty minutes into the conversation the customer mentions the first floor going up next year for his son. The 5 kW design is not slightly off. It is wrong, because it solves for a house that will not exist in eighteen months.

The Indian context makes this sharper than it looks. Household sanctioned load in India sits typically between 1 to 2 kW per customer according to CEA reporting for FY2022-24. Design to the current bill and you are designing to a constraint the customer is already straining against, not to the load they will actually run once the system removes their reason to ration. deccanherald

This is not hypothetical. WRI India documents a household that installed a modest 1 kWp system in Hyderabad in 2012, expanding it to 5 kWp in 2024. Five times the original system. The same report notes that current subsidy structure limits customization options for homeowners looking to expand their solar installations in the future. CEEWCEEW

Commercial is the same problem with more zeros. A unit running one shift today, planning a second from March, needs headroom the current bill cannot show you. Size for present load and you strand the customer's expansion behind a system somebody will have to tear into.

You cannot get this from a bill. You get it from asking, and you can only ask in person.

What actually changes when you are standing on the roof?

Four things, in this order, and only the first two are design changes.

Size comes first, because everything else follows from it. Adding or removing panels to hit the right kW for present load plus planned growth. This is the decision that determines whether the customer calls you back in three years grateful or annoyed.

Then placement. Rearranging modules across the roof that actually exists, working around the water tank, the parapet, the stairwell head, the neighbour's building that throws shade after 3 PM. Setting tilt and orientation on the sections available to maximise generation, not on an idealised rectangle.

Then OEM. The customer says Tata. Or Waaree. Or they want Sungrow rather than Solis because their cousin's plant runs one. This preference is not a technical objection to be overcome. It is a trust decision, and it is often non-negotiable to them even when the alternative is technically identical.

Then the commercial layer. Cost, payment terms, generation estimate, ROI, capital recovery period. Every one of these moves when the size moves.

That last group is where deals are won and lost, and it is the group most design tools leave you to rebuild by hand.

What happens to the lead while the proposal sits with your designer?

It gets shopped, and the timing could not be worse.

Walk the sequence honestly. The rep leaves with notes. Briefs the designer, who is mid-way through two other projects. The revised layout comes back a day or two later. Someone rebuilds the commercial sheet. The proposal goes out.

Meanwhile the customer, who is now actively in buying mode because you just spent an hour making them think seriously about solar, calls the next two names on their list. Your proposal lands third, next to two others, and the only variable left to compare on is price.

The research on response speed is old, large, and consistent. The 2007 MIT and InsideSales Lead Response Management study by James Oldroyd found that leads called within 5 minutes were 21 times more likely to be qualified than leads called after 30 minutes. The follow-up appeared in Harvard Business Review in 2011 as "The Short Life of Online Sales Leads," which audited 2,241 US firms and found an average first response time of 42 hours. SolarQuarterCasey Response AI

One caveat worth stating plainly, because it makes the point stronger rather than weaker: the study did not measure close rates. It measured contact and qualification. Speed does not win the deal. Speed decides whether you are still in the conversation when the deal is won. SolarQuarter

And there is India-specific evidence that this stage is already fragile. CEEW's June 2026 national survey found that among households who initiated the process, nearly half (43 per cent) reported a smooth end-to-end experience, and for those who encountered friction, the barriers were concentrated at specific, identifiable stages such as application submission, vendor selection, and net metering approvals.

Vendor selection is already one of the three hardest steps for your customer. Your four-day proposal gap is happening inside it.

Why does this have to happen in person at all?

Because Indian households want it to, and the data is explicit on this point.

CEEW's survey of 17,094 households across 21 states and 1 union territory, representing 98 per cent of India's population, found that nearly 71 per cent of the households surveyed reported trust in government departments and officials as credible sources of information on new government schemes, and preference towards in-person visits as the primary mode of communication.

The site visit is not overhead to be optimised away. It is the channel your customer actually prefers, and it is the only setting where the sizing conversation can happen properly.

The problem was never the visit. The problem is that the visit produces information your design tool cannot receive until you get back to a desk.

Can you revise a solar design in front of the customer on a phone?

Yes, and this is where the argument stops being about speed and becomes about the conversation itself.

Reslink is built mobile-first and runs under 10 MB on any Android or iOS phone. That size matters more than it sounds. Your field team is not carrying workstations, and a rep in a tier-2 city is working on the phone they already own, on whatever network the site has.

AI-led panel placement handles the layout, so the rep is adjusting a design rather than drawing one from scratch. Change the size and the layout responds. Move panels off a shaded section and the generation figures follow. Swap the module brand to the one the customer named and the commercial numbers update with it.

It works exactly as seamlessly on desktop as on mobile. This is not a stripped-down field version of a real tool. It is the same tool, and the desk is simply one more place you can use it.

What does the customer see while you are doing this?

An interactive 3D render of their own roof, which they can move around and respond to.

This is the difference between describing a system and showing one. The customer rotates the view, looks at the east side, asks what happens if the panels come off that section because the water tank is going there next year. You make the change. They watch the layout redraw and the numbers move.

They are not receiving a proposal at that point. They are shaping one. That changes what they feel when it is time to sign, and it changes what they tell their neighbours afterward.

That last part is worth taking seriously as a business input. CEEW found that more than 90 per cent adopters reported a positive post-installation experience, especially with bill savings and system performance, and 87 per cent were willing to recommend their solar vendors. Referral is the cheapest lead source you will ever have, and it is earned during the sale, not after it.

Does the revised design carry through to BOM and procurement?

Yes. Once the customer accepts the design, the same file produces the bill of materials and the component list, ready to procure against.

No re-entry. No second version. No gap between what the customer agreed to on the roof and what your procurement team actually orders. The design the customer shaped is the design that gets built.

This closes the loop that most EPCs leave open, where the on-site conversation, the office design, and the purchase order are three separate documents that drift apart.

How does this change the commercial proposal, not just the drawing?

The proposal regenerates alongside the design, with ROI, generation data, capital recovery period, payment terms, and the OEM the customer chose.

This is the part that makes the difference commercially. A revised drawing is useful. A revised drawing plus a revised financial case, delivered before you walk down the stairs, is a different sales conversation entirely. The customer locks in the brands they wanted before they pay, and sees the returns calculated on the system they helped build, not a template.

Common mistakes

1. Sizing to the current electricity bill and ignoring the expansion the customer just told you about
2. Treating an OEM preference as an objection to overcome rather than a specification to honour
3. Leaving the site with any open question that needs a follow-up call to close
4. Promising a revised proposal "by tomorrow" and delivering on day four
5. Showing a 2D layout and expecting a homeowner to picture their own roof from it
6. Redesigning at the office and never confirming the customer agrees with what changed

What Indian EPCs should do now

Start with measurement, not software. Pull your last ten site visits and log two numbers: how many days passed between the visit and the proposal reaching the customer, and how many of those leads asked for a size change after you met them.

If the second number is high and the first number is more than a day, your constraint is not lead generation. It is the gap between the conversation and the document.

Most small EPCs try to solve this by hiring a designer. That adds capacity but not speed, because the bottleneck is not how fast the designer works. It is that the design lives on a machine your rep cannot reach from a rooftop.

The scale of what is moving makes this urgent. As of 31 May 2026, PMSGY has received 6.9 million applications and 4 million households have been covered under the scheme. To hit the national target, India needs to sustain its current momentum to solarise 0.6 million households per month between June 2026 to March 2027. Every one of those households will choose between EPCs, and most will choose partly on who felt organised.

Bottom line

The site visit is not data collection for a design that happens later. It is the design.

Everything that determines system size, panel placement, brand selection and commercial terms comes out of that hour with the customer. Every hour between that conversation and the proposal is an hour a competitor can use, and your customer is already finding vendor selection one of the hardest parts of the process. Close the loop on the roof.

FAQ

Q1. Why can't I just finalise the solar design before the site visit?
Because the design depends on information that does not exist in aerial imagery or a past electricity bill. Future load, planned construction, roof obstructions and brand preference all come out in conversation. A pre-visit design is a useful starting point, not a deliverable.

Q2. What is the most common reason a solar system size changes after meeting the customer?
Planned load growth. A family adding a floor, an appliance upgrade, an EV, or a commercial unit adding a shift. Indian sanctioned loads sit at 1 to 2 kW per customer on average, so the current bill routinely understates real requirement. deccanherald

Q3. How do you size a residential system for future expansion?
Ask directly about construction plans, family size changes, and appliance purchases over the next three to five years, then size for that load rather than today's. Confirm the roof can physically take the future array before you commit to a layout.

Q4. Can a sales rep without design training make these changes on site?
Yes. AI-led panel placement generates the layout, so the rep is adjusting an existing design rather than engineering one. The judgement required is sales judgement, which is what the rep already has.

Q5. What phone do I need to run Reslink on site?
Any Android or iOS phone. The app is under 10 MB, so it works on the devices field teams already carry rather than requiring a high-end handset.

Q6. Can the customer see the 3D design themselves?
Yes. The render is interactive, so the customer can move around it, look at their own roof from different angles, and point at what they want changed while you are still there.

Q7. Does the customer's OEM preference flow through to the proposal automatically?
Yes. Selecting a different module or inverter brand updates the design and the commercial proposal together, including cost and generation figures, so the customer sees the actual implication of their preference rather than a promise to revise later.

Q8. Does the accepted design carry through to the bill of materials?
Yes. The same design produces the BOM and component list ready for procurement, so there is no gap between what the customer agreed to and what gets ordered.

Sources

1. Chaudhary, M., Purohit, S., Vijayan, M., and Tyagi, B. 2026. What Drives Rooftop Solar Installation Decisions in Indian Homes? Understanding Household Decision-making Through a Pan-India Survey. New Delhi: Council on Energy, Environment and Water. Survey of 17,094 households across 21 states and 1 UT.

• Central Electricity Authority, FY2022-24 household sanctioned load data, as reported in Nexdigm India Rooftop Solar Market Report.

1. WRI India, "12 Years Under the Sun: Two Rooftop Solar Journeys," February 2025.
2. Oldroyd, J. Lead Response Management Study. MIT / InsideSales.com, 2007. Six companies, 15,000+ leads, 100,000+ call attempts.
3. Oldroyd, J., McElheran, K., and Elkington, D. "The Short Life of Online Sales Leads." Harvard Business Review, March 2011. Audit of 2,241 US firms.
4. Reslink product specifications: app size, platform support, AI-led panel placement, interactive 3D render, BOM generation, commercial proposal outputs.

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